diff --git a/src/Dialogs.c b/src/Dialogs.c
index 3652c9595..eae79f9c7 100644
--- a/src/Dialogs.c
+++ b/src/Dialogs.c
@@ -144,7 +144,7 @@ int MsgBoxLng(int iType, UINT uIdMsg, ...)
       StringCchCat(szText, COUNTOF(szText), lpMsgBuf);
       LocalFree(lpMsgBuf);
     }
-    wcht = *CharPrev(szText, StrEnd(szText));
+    wcht = *CharPrev(szText, StrEnd(szText, COUNTOF(szText)));
     if (IsCharAlphaNumeric(wcht) || wcht == '"' || wcht == '\'')
       StringCchCat(szText, COUNTOF(szText), L".");
   }
@@ -415,7 +415,7 @@ static DWORD CALLBACK _LoadRtfCallback(
 )
 {
   LPSTR* pstr = (LPSTR*)dwCookie;
-  LONG len = (LONG)strlen(*pstr);
+  LONG len = (LONG)StringCchLenA(*pstr,0);
 
   if (len < cb)
   {
@@ -3359,7 +3359,7 @@ int Toolbar_SetButtons(HWND hwnd, int cmdBase, LPCWSTR lpszButtons, LPCTBBUTTON
   TrimStringW(tchButtons);
   WCHAR *p = StrStr(tchButtons, L"  ");
   while (p) {
-    MoveMemory((WCHAR*)p, (WCHAR*)p + 1, (lstrlen(p) + 1) * sizeof(WCHAR));
+    MoveMemory((WCHAR*)p, (WCHAR*)p + 1, (StringCchLen(p,0) + 1) * sizeof(WCHAR));
     p = StrStr(tchButtons, L"  ");  // next
   }
   c = (int)SendMessage(hwnd, TB_BUTTONCOUNT, 0, 0);
@@ -3380,7 +3380,7 @@ int Toolbar_SetButtons(HWND hwnd, int cmdBase, LPCWSTR lpszButtons, LPCTBBUTTON
         }
       }
     }
-    p = StrEnd(p) + 1;
+    p = StrEnd(p,0) + 1;
   }
   return((int)SendMessage(hwnd, TB_BUTTONCOUNT, 0, 0));
 }
@@ -3511,7 +3511,7 @@ DLGTEMPLATE* LoadThemedDialogTemplate(LPCTSTR lpDialogTemplateID, HINSTANCE hIns
   pbNew = (BYTE*)wchFaceName;
 
   pb = DialogTemplate_GetFontSizeField(pTemplate);
-  cbOld = (int)(bHasFont ? cbFontAttr + 2 * (lstrlen((WCHAR*)(pb + cbFontAttr)) + 1) : 0);
+  cbOld = (int)(bHasFont ? cbFontAttr + 2 * (StringCchLen((WCHAR*)(pb + cbFontAttr),0) + 1) : 0);
 
   pOldControls = (BYTE*)(((DWORD_PTR)pb + cbOld + 3) & ~(DWORD_PTR)3);
   pNewControls = (BYTE*)(((DWORD_PTR)pb + cbNew + 3) & ~(DWORD_PTR)3);
diff --git a/src/Edit.c b/src/Edit.c
index 8307273aa..38f3a5f7c 100644
--- a/src/Edit.c
+++ b/src/Edit.c
@@ -339,7 +339,7 @@ void EditInitWordDelimiter(HWND hwnd)
   StringCchCopyA(WhiteSpaceCharsAccelerated, COUNTOF(WhiteSpaceCharsAccelerated), WhiteSpaceCharsDefault);
 
   // add only 7-bit-ASCII chars to accelerated whitespace list
-  for (size_t i = 0; i < strlen(whitesp); i++) {
+  for (size_t i = 0; i < StringCchLenA(whitesp, ANSI_CAHR_BUFFER); i++) {
     if (whitesp[i] & 0x7F) {
       if (!StrChrA(WhiteSpaceCharsAccelerated, whitesp[i])) {
         StringCchCatNA(WhiteSpaceCharsAccelerated, COUNTOF(WhiteSpaceCharsAccelerated), &(whitesp[i]), 1);
@@ -350,7 +350,7 @@ void EditInitWordDelimiter(HWND hwnd)
   // construct word char array
   StringCchCopyA(WordCharsAccelerated, COUNTOF(WordCharsAccelerated), WordCharsDefault); // init
   // add punctuation chars not listed in white-space array
-  for (size_t i = 0; i < strlen(PunctuationCharsDefault); i++) {
+  for (size_t i = 0; i < StringCchLenA(PunctuationCharsDefault, ANSI_CAHR_BUFFER); i++) {
     if (!StrChrA(WhiteSpaceCharsAccelerated, PunctuationCharsDefault[i])) {
       StringCchCatNA(WordCharsAccelerated, COUNTOF(WordCharsAccelerated), &(PunctuationCharsDefault[i]), 1);
     }
@@ -367,7 +367,7 @@ void EditInitWordDelimiter(HWND hwnd)
     WideCharToMultiByteStrg(CP_ACP, buffer, autocompl);
   }
   // add only 7-bit-ASCII chars to accelerated whitespace list
-  for (size_t i = 0; i < strlen(autocompl); i++) {
+  for (size_t i = 0; i < StringCchLenA(autocompl, ANSI_CAHR_BUFFER); i++) {
     if (autocompl[i] & 0x7F) {
       if (!StrChrA(AutoCompleteWordASCII, autocompl[i])) {
         StringCchCatNA(AutoCompleteWordASCII, COUNTOF(AutoCompleteWordASCII), &(autocompl[i]), 1);
@@ -721,7 +721,7 @@ char* EditGetClipboardText(HWND hwnd, bool bCheckEncoding, int* pLineCount, int*
 bool EditSetClipboardText(HWND hwnd, const char* pszText)
 {
   if (!IsClipboardFormatAvailable(CF_UNICODETEXT)) {
-    SciCall_CopyText((DocPos)strlen(pszText), pszText);
+    SciCall_CopyText((DocPos)StringCchLenA(pszText,0), pszText);
     return true;
   }
 
@@ -861,19 +861,19 @@ bool EditCopyAppend(HWND hwnd, bool bAppend)
   HANDLE hOld   = GetClipboardData(CF_UNICODETEXT);
   WCHAR* pszOld = GlobalLock(hOld);
 
-  int sizeNew = 0;
+  size_t sizeNew = 0;
   if (pszOld && pszTextW)
-    sizeNew = lstrlen(pszOld) + lstrlen(pszTextW) + 1;
+    sizeNew = StringCchLen(pszOld,0) + StringCchLen(pszTextW,0) + 1;
 
   const  WCHAR *pszSep = L"\r\n";
-  sizeNew += (int)lstrlen(pszSep);
+  sizeNew += StringCchLen(pszSep,0);
 
   // Copy Clip
   WCHAR* pszNewTextW = LocalAlloc(LPTR, sizeof(WCHAR) * sizeNew);
   
-  if (pszOld && pszNewTextW)
+  if (pszOld && pszNewTextW) {
     StringCchCopy(pszNewTextW, sizeNew, pszOld);
-
+  }
   GlobalUnlock(hOld);
   CloseClipboard();
 
@@ -1888,7 +1888,7 @@ void EditChar2Hex(HWND hwnd) {
   }
   SendMessage(hwnd, SCI_REPLACESEL, 0, (LPARAM)ch);
 
-  const DocPos iReplLen = StringCchLenA(ch, COUNTOF(ch));
+  DocPos const iReplLen = (DocPos)StringCchLenA(ch, COUNTOF(ch));
 
   if (iCurPos < iAnchorPos) {
     EditSelectEx(hwnd, iCurPos + iReplLen, iCurPos, -1, -1);
@@ -2067,7 +2067,7 @@ void EditModifyNumber(HWND hwnd,bool bIncrease) {
           StringCchPrintfA(chFormat, COUNTOF(chFormat), "%%0%ii", iWidth);
           StringCchPrintfA(chNumber, COUNTOF(chNumber), chFormat, iNumber);
           SciCall_ReplaceSel(chNumber);
-          SciCall_SetSel(iSelStart, iSelStart + StringCchLenA(chNumber, COUNTOF(chNumber)));
+          SciCall_SetSel(iSelStart, iSelStart + (DocPos)StringCchLenA(chNumber, COUNTOF(chNumber)));
         }
       }
       else if (sscanf_s(chNumber, "%x", &iNumber) == 1) {
@@ -2093,7 +2093,7 @@ void EditModifyNumber(HWND hwnd,bool bIncrease) {
 
           StringCchPrintfA(chNumber, COUNTOF(chNumber), chFormat, iNumber);
           SciCall_ReplaceSel(chNumber);
-          SciCall_SetSel(iSelStart, iSelStart + StringCchLenA(chNumber, COUNTOF(chNumber)));
+          SciCall_SetSel(iSelStart, iSelStart + (DocPos)StringCchLenA(chNumber, COUNTOF(chNumber)));
         }
       }
     }
@@ -2866,7 +2866,7 @@ void EditAlignText(HWND hwnd,int nMode)
                 WCHAR wchNewLineBuf[BUFSIZE_ALIGN * 3] = { L'\0' };
                 int length = BUFSIZE_ALIGN * 3;
                 StringCchCopy(wchNewLineBuf,COUNTOF(wchNewLineBuf),pWords[0]);
-                p = StrEnd(wchNewLineBuf);
+                p = StrEnd(wchNewLineBuf, COUNTOF(wchNewLineBuf));
 
                 for (i = 1; i < iWords; i++) {
                   for (j = 0; j < iSpacesPerGap; j++) {
@@ -2878,7 +2878,7 @@ void EditAlignText(HWND hwnd,int nMode)
                     *p = 0;
                   }
                   StringCchCat(p,(length - StringCchLenW(wchNewLineBuf,COUNTOF(wchNewLineBuf))),pWords[i]);
-                  p = StrEnd(p);
+                  p = StrEnd(p,0);
                 }
 
                 int cch = WideCharToMultiByteStrg(Encoding_SciCP,wchNewLineBuf,g_pTempLineBuffer) - 1;
@@ -2892,13 +2892,13 @@ void EditAlignText(HWND hwnd,int nMode)
 
                 WCHAR wchNewLineBuf[BUFSIZE_ALIGN] = { L'\0' };
                 StringCchCopy(wchNewLineBuf,COUNTOF(wchNewLineBuf),pWords[0]);
-                p = StrEnd(wchNewLineBuf);
+                p = StrEnd(wchNewLineBuf, COUNTOF(wchNewLineBuf));
 
                 for (int i = 1; i < iWords; i++) {
                   *p++ = L' ';
                   *p = 0;
                   StringCchCat(p,(COUNTOF(wchNewLineBuf) - StringCchLenW(wchNewLineBuf,COUNTOF(wchNewLineBuf))),pWords[i]);
-                  p = StrEnd(p);
+                  p = StrEnd(p,0);
                 }
 
                 int cch = WideCharToMultiByteStrg(Encoding_SciCP,wchNewLineBuf,g_pTempLineBuffer) - 1;
@@ -2937,7 +2937,7 @@ void EditAlignText(HWND hwnd,int nMode)
                   StringCchCat(p,(COUNTOF(wchNewLineBuf) - StringCchLenW(wchNewLineBuf,COUNTOF(wchNewLineBuf))),L" ");
                   iOddSpaces--;
                 }
-                p = StrEnd(p);
+                p = StrEnd(p,0);
               }
 
               int cch = WideCharToMultiByteStrg(Encoding_SciCP,wchNewLineBuf,g_pTempLineBuffer) - 1;
@@ -3002,8 +3002,8 @@ void EditEncloseSelection(HWND hwnd, LPCWSTR pwszOpen, LPCWSTR pwszClose)
   if (StrIsNotEmpty(pwszOpen)) { WideCharToMultiByteStrg(Encoding_SciCP, pwszOpen, mszOpen); }
   if (StrIsNotEmpty(pwszClose)) { WideCharToMultiByteStrg(Encoding_SciCP, pwszClose, mszClose); }
 
-  const DocPos iLenOpen = StringCchLenA(mszOpen, COUNTOF(mszOpen));
-  const DocPos iLenClose = StringCchLenA(mszClose, COUNTOF(mszClose));
+  DocPos const iLenOpen = (DocPos)StringCchLenA(mszOpen, COUNTOF(mszOpen));
+  DocPos const iLenClose = (DocPos)StringCchLenA(mszClose, COUNTOF(mszClose));
 
   _ENTER_TARGET_TRANSACTION_;
 
@@ -3042,7 +3042,7 @@ void EditToggleLineComments(HWND hwnd, LPCWSTR pwszComment, bool bInsertAtStart)
   if (StrIsNotEmpty(pwszComment)) {
     WideCharToMultiByte(Encoding_SciCP, 0, pwszComment, -1, mszComment, COUNTOF(mszComment), NULL, NULL);
   }
-  const DocPos cchComment = StringCchLenA(mszComment, COUNTOF(mszComment));
+  DocPos const cchComment = (DocPos)StringCchLenA(mszComment, COUNTOF(mszComment));
 
   if (cchComment == 0) { return; }
 
@@ -3661,7 +3661,7 @@ void EditCompressBlanks(HWND hwnd)
 
         _LEAVE_TARGET_TRANSACTION_;
 
-        const DocPos iNewLen = StringCchLenA(pszOut, LocalSize(pszOut));
+        DocPos const iNewLen = (DocPos)StringCchLenA(pszOut, LocalSize(pszOut));
 
         if (iCurPos < iAnchorPos) {
           EditSelectEx(hwnd, iCurPos + iNewLen, iCurPos, -1, -1);
@@ -4383,7 +4383,7 @@ void EditSortLines(HWND hwnd, int iSortFlags)
   }
   FreeMem(pLines);
 
-  DocPos const iResultLength = StringCchLenA(pmszResult, lenRes) + ((cEOLMode == SC_EOL_CRLF) ? 2 : 1);
+  DocPos const iResultLength = (DocPos)StringCchLenA(pmszResult, lenRes) + ((cEOLMode == SC_EOL_CRLF) ? 2 : 1);
   if (!bIsRectangular) {
     if (iAnchorPos > iCurPos) {
       iCurPos = iSelStart;
@@ -6171,7 +6171,7 @@ bool EditReplace(HWND hwnd, LPCEDITFINDREPLACE lpefr) {
   DocPos _start = start;
   g_iReplacedOccurrences = 0;
 
-  const DocPos iPos = _FindInTarget(hwnd, lpefr->szFind, StringCchLenA(lpefr->szFind, FRMOD_NORM), 
+  DocPos const iPos = _FindInTarget(hwnd, lpefr->szFind, (DocPos)StringCchLenA(lpefr->szFind, FRMOD_NORM),
     (int)(lpefr->fuFlags), &start, &end, false, false);
 
   // w/o selection, replacement string is put into current position
@@ -6520,7 +6520,7 @@ void EditMarkAll(HWND hwnd, char* pszFind, int flags, DocPos rangeStart, DocPos
     flags |= (bMatchCase ? SCFIND_MATCHCASE : 0);
   }
   else {
-    iFindLength = StringCchLenA(pszFind, FNDRPL_BUFFER);
+    iFindLength = (DocPos)StringCchLenA(pszFind, FNDRPL_BUFFER);
   }
 
   if (iFindLength > 0) {
@@ -6711,11 +6711,11 @@ void EditUpdateUrlHotspots(HWND hwnd, DocPos startPos, DocPos endPos, bool bActi
     "(?:\\([-A-Z0-9+&@#/%=~_|$?!:,.]*\\)|[-A-Z0-9+&@#/%=~_|$?!:,.])*"
     "(?:\\([-A-Z0-9+&@#/%=~_|$?!:,.]*\\)|[A-Z0-9+&@#/%=~_|$])";
 
-  const int iRegExLen = (int)strlen(pszUrlRegEx);
+  int const iRegExLen = (int)StringCchLenA(pszUrlRegEx,0);
 
   if (startPos < 0) { // current line only
-    DocPos currPos = SciCall_GetCurrentPos();
-    DocLn lineNo = SciCall_LineFromPosition(currPos);
+    DocPos const currPos = SciCall_GetCurrentPos();
+    DocLn const lineNo = SciCall_LineFromPosition(currPos);
     startPos = SciCall_PositionFromLine(lineNo);
     endPos = SciCall_GetLineEndPosition(lineNo);
   }
@@ -6726,11 +6726,11 @@ void EditUpdateUrlHotspots(HWND hwnd, DocPos startPos, DocPos endPos, bool bActi
   DocPos end = endPos;
   
   do {
-    DocPos iPos = _FindInTarget(hwnd, pszUrlRegEx, iRegExLen, SCFIND_NP3_REGEX, &start, &end, false, FRMOD_IGNORE);
+    DocPos const iPos = _FindInTarget(hwnd, pszUrlRegEx, iRegExLen, SCFIND_NP3_REGEX, &start, &end, false, FRMOD_IGNORE);
 
-    if (iPos < 0)
+    if (iPos < 0) {
       break; // not found
-
+    }
     DocPos mlen = end - start;
     if ((mlen <= 0) || ((iPos + mlen) > endPos))
       break; // wrong match
@@ -7763,7 +7763,7 @@ void  EditSetBookmarkList(HWND hwnd, LPCWSTR pszBookMarks)
   while (*p1) {
     const WCHAR* p2 = StrChr(p1, L';');
     if (!p2)
-      p2 = StrEnd(p1);
+      p2 = StrEnd(p1,0);
     StringCchCopyNW(lnNum, COUNTOF(lnNum), p1, min((int)(p2 - p1), 16));
     long long iLine = 0;
     if (swscanf_s(lnNum, L"%lld", &iLine) == 1) {
diff --git a/src/Helpers.c b/src/Helpers.c
index 5399be403..6e8cadac4 100644
--- a/src/Helpers.c
+++ b/src/Helpers.c
@@ -74,7 +74,7 @@ CHAR* StrCutIA(CHAR* s,const CHAR* pattern)
   do {
     p = StrStrIA(s,pattern);
     if (p) {
-      CHAR* q = p + strlen(pattern);
+      CHAR* q = p + StringCchLenA(pattern,0);
       while (*p != '\0') { *p++ = *q++; }
     }
   } while (p);
@@ -87,7 +87,7 @@ WCHAR* StrCutIW(WCHAR* s,const WCHAR* pattern)
   do {
     p = StrStrIW(s,pattern);
     if (p) {
-      WCHAR* q = p + lstrlen(pattern);
+      WCHAR* q = p + StringCchLen(pattern,0);
       while (*p != L'\0') { *p++ = *q++; }
     }
   } while (p);
@@ -114,7 +114,7 @@ bool StrDelChrA(LPSTR pszSource, LPCSTR pCharsToRemove)
       ++prem;
     }
     if (prem > pch) {
-      MoveMemory(pch, prem, sizeof(CHAR)*(strlen(prem) + 1));
+      MoveMemory(pch, prem, sizeof(CHAR)*(StringCchLenA(prem,0) + 1));
     }
     ++pch;
   }
@@ -166,7 +166,7 @@ bool SetClipboardTextW(HWND hwnd, LPCWSTR pszTextW)
     return false;
   }
 
-  int cchTextW = lstrlen(pszTextW) + 1;
+  size_t cchTextW = StringCchLenW(pszTextW,0) + 1;
   HANDLE hData = GlobalAlloc(GMEM_MOVEABLE | GMEM_ZEROINIT, sizeof(WCHAR) * cchTextW);
   WCHAR* pszNew = GlobalLock(hData);
 
@@ -204,7 +204,7 @@ int IniSectionGetString(
         return((int)StringCchLen(lpReturnedString, cchReturnedString));
       }
       else
-        p = StrEnd(p) + 1;
+        p = StrEnd(p,0) + 1;
     }
   }
   StringCchCopyN(lpReturnedString, cchReturnedString, lpDefault, cchReturnedString);
@@ -230,7 +230,7 @@ int IniSectionGetInt(LPCWSTR lpCachedIniSection, LPCWSTR lpName, int iDefault)
           return(iDefault);
       }
       else
-        p = StrEnd(p) + 1;
+        p = StrEnd(p,0) + 1;
     }
   }
   return(iDefault);
@@ -255,7 +255,7 @@ UINT IniSectionGetUInt(LPCWSTR lpCachedIniSection, LPCWSTR lpName, UINT uDefault
           return(uDefault);
       }
       else
-        p = StrEnd(p) + 1;
+        p = StrEnd(p,0) + 1;
     }
   }
   return(uDefault);
@@ -279,7 +279,7 @@ DocPos IniSectionGetPos(LPCWSTR lpCachedIniSection, LPCWSTR lpName, DocPos posDe
           return (DocPos)posDefault;
       }
       else
-        p = StrEnd(p) + 1;
+        p = StrEnd(p,0) + 1;
     }
   }
   return (DocPos)posDefault;
@@ -292,15 +292,15 @@ bool IniSectionSetString(LPWSTR lpCachedIniSection,LPCWSTR lpName,LPCWSTR lpStri
   WCHAR* p = lpCachedIniSection;
   if (p) {
     while (*p) {
-      p = StrEnd(p) + 1;
+      p = StrEnd(p,0) + 1;
     }
     StringCchPrintf(tch,COUNTOF(tch),L"%s=%s",lpName,lpString);
     StringCchCopy(p,COUNTOF(tch),tch);
-    p = StrEnd(p) + 1;
-    *p = 0;
-    return(true);
+    p = StrEnd(p,0) + 1;
+    *p = L'\0';
+    return true;
   }
-  return(false);
+  return false;
 }
 
 
@@ -330,7 +330,7 @@ DWORD GetLastErrorToMsgBox(LPWSTR lpszFunction, DWORD dwErrID)
   // Display the error message and exit the process
 
   LPVOID lpDisplayBuf = (LPVOID)LocalAlloc(LMEM_ZEROINIT,
-    (lstrlen((LPCWSTR)lpMsgBuf) + lstrlen((LPCWSTR)lpszFunction) + 80) * sizeof(WCHAR));
+    (StringCchLenW((LPCWSTR)lpMsgBuf,0) + StringCchLenW((LPCWSTR)lpszFunction,0) + 80) * sizeof(WCHAR));
 
   StringCchPrintf((LPWSTR)lpDisplayBuf, LocalSize(lpDisplayBuf) / sizeof(WCHAR),
     L"Error: '%s' failed with error id %d:\n%s.\n", lpszFunction, dwErrID, lpMsgBuf);
@@ -1144,7 +1144,7 @@ bool StrLTrim(LPWSTR pszSource,LPCWSTR pszTrimChars)
   LPWSTR psz = pszSource;
   while (StrChrI(pszTrimChars, *psz)) { ++psz; }
 
-  MoveMemory(pszSource,psz,sizeof(WCHAR)*(lstrlen(psz) + 1));
+  MoveMemory(pszSource,psz,sizeof(WCHAR)*(StringCchLenW(psz,0) + 1));
 
   return true;
 }
@@ -1164,10 +1164,10 @@ bool TrimStringA(LPSTR lpString)
   LPSTR psz = lpString;
   while (*psz == ' ') { psz = CharNextA(psz); }
 
-  MoveMemory(lpString, psz, sizeof(CHAR)*(strlen(psz) + 1));
+  MoveMemory(lpString, psz, sizeof(CHAR)*(StringCchLenA(psz,0) + 1));
 
   // Trim right
-  psz = StrEndA(lpString);
+  psz = StrEndA(lpString,0);
   while (*(psz = CharPrevA(lpString, psz)) == ' ') { *psz = '\0'; }
 
   return true;
@@ -1187,10 +1187,10 @@ bool TrimStringW(LPWSTR lpString)
   LPWSTR psz = lpString;
   while (*psz == L' ') { psz = CharNextW(psz); }
 
-  MoveMemory(lpString,psz,sizeof(WCHAR)*(lstrlen(psz) + 1));
+  MoveMemory(lpString,psz,sizeof(WCHAR)*(StringCchLenA(psz,0) + 1));
 
   // Trim right
-  psz = StrEndW(lpString);
+  psz = StrEndW(lpString,0);
   while (*(psz = CharPrevW(lpString, psz)) == L' ') { *psz = L'\0'; }
 
   return true;
@@ -1251,7 +1251,7 @@ bool ExtractFirstArgument(LPCWSTR lpArgs, LPWSTR lpArg1, LPWSTR lpArg2, int len)
 //
 void PrepareFilterStr(LPWSTR lpFilter)
 {
-  LPWSTR psz = StrEnd(lpFilter);
+  LPWSTR psz = StrEnd(lpFilter,0);
   while (psz != lpFilter)
   {
     if (*(psz = CharPrev(lpFilter,psz)) == L'|')
@@ -1384,7 +1384,7 @@ DWORD_PTR SHGetFileInfo2(LPCWSTR pszPath,DWORD dwFileAttributes,
 //
 //  FormatNumberStr()
 //
-int FormatNumberStr(LPWSTR lpNumberStr)
+size_t FormatNumberStr(LPWSTR lpNumberStr)
 {
   static WCHAR szSep[5] = { L'\0' };
   static WCHAR szGrp[11] = { L'\0' };
@@ -1410,18 +1410,18 @@ int FormatNumberStr(LPWSTR lpNumberStr)
     swscanf_s(szGrp, L"%i;%i;%i;%i", &iPlace[0], &iPlace[1], &iPlace[2], &iPlace[3]);
   }
   if (iPlace[0] <= 0) {
-    return lstrlen(lpNumberStr); 
+    return StringCchLen(lpNumberStr,0);
   }
 
-  if (lstrlen(lpNumberStr) > iPlace[0]) {
+  if (StringCchLen(lpNumberStr,0) > iPlace[0]) {
 
-    WCHAR* ch = StrEnd(lpNumberStr);
+    WCHAR* ch = StrEnd(lpNumberStr,0);
 
     int  iCnt = 0;
     int  i = 0;
     while ((ch = CharPrev(lpNumberStr, ch)) != lpNumberStr) {
       if (((++iCnt) % iPlace[i]) == 0) {
-        MoveMemory(ch + 1, ch, sizeof(WCHAR)*(lstrlen(ch) + 1));
+        MoveMemory(ch + 1, ch, sizeof(WCHAR)*(StringCchLen(ch,0) + 1));
         *ch = szSep[0];
         i = (i < 3) ? (i + 1) : 3;
         if (iPlace[i] == 0) { --i; } else if (iPlace[i] < 0) { break; }
@@ -1429,7 +1429,7 @@ int FormatNumberStr(LPWSTR lpNumberStr)
       }
     }
   }
-  return lstrlen(lpNumberStr);
+  return StringCchLen(lpNumberStr,0);
 }
 
 
@@ -2226,7 +2226,7 @@ void UrlUnescapeEx(LPWSTR lpURL, LPWSTR lpUnescaped, DWORD* pcchUnescaped)
 
   int posIn = 0;
   WCHAR buf[5] = { L'\0' };
-  int lastEsc = lstrlen(lpURL) - 2;
+  size_t lastEsc = StringCchLenW(lpURL,0) - 2;
   int code;
 
   while ((posIn < lastEsc) && (posOut < outLen))
@@ -2334,7 +2334,7 @@ int ReadVectorFromString(LPCWSTR wchStrg, int iVector[], int iCount, int iMin, i
   // ensure single spaces only
   WCHAR *p = StrStr(wchTmpBuff, L"  ");
   while (p) {
-    MoveMemory((WCHAR*)p, (WCHAR*)p + 1, (lstrlen(p) + 1) * sizeof(WCHAR));
+    MoveMemory((WCHAR*)p, (WCHAR*)p + 1, (StringCchLenW(p,0) + 1) * sizeof(WCHAR));
     p = StrStr(wchTmpBuff, L"  ");  // next
   }
   // separate values
@@ -2356,7 +2356,7 @@ int ReadVectorFromString(LPCWSTR wchStrg, int iVector[], int iCount, int iMin, i
         iVector[n++] = clampi(iValue, iMin, iMax);
       }
     }
-    p = StrEnd(p) + 1;
+    p = StrEnd(p,0) + 1;
   }
   return n;
 }
diff --git a/src/Helpers.h b/src/Helpers.h
index d57b8bd31..8e4433d46 100644
--- a/src/Helpers.h
+++ b/src/Helpers.h
@@ -62,46 +62,43 @@ void DbgLog(const char *fmt, ...);
 // ============================================================================
 
 // swap 
-static inline void swapi(int* a, int* b) { int t = *a;  *a = *b;  *b = t; }
-static inline void swapos(DocPos* a, DocPos* b) { DocPos t = *a;  *a = *b;  *b = t; }
+inline void swapi(int* a, int* b) { int t = *a;  *a = *b;  *b = t; }
+inline void swapos(DocPos* a, DocPos* b) { DocPos t = *a;  *a = *b;  *b = t; }
 
 // clamp
-static inline int clampi(int x, int lower, int upper) {
+inline int clampi(int x, int lower, int upper) {
   return (x < lower) ? lower : ((x > upper) ? upper : x);
 }
 
-static inline unsigned clampu(unsigned x, unsigned lower, unsigned upper) {
+inline unsigned clampu(unsigned x, unsigned lower, unsigned upper) {
   return (x < lower) ? lower : ((x > upper) ? upper : x);
 }
 
 
 // Is the character an octal digit?
-static inline bool IsDigit(CHAR ch) { return ((ch >= '0') && (ch <= '9')); }
-static inline bool IsDigitW(WCHAR wch) { return ((wch >= L'0') && (wch <= L'9')); }
+inline bool IsDigitA(CHAR ch) { return ((ch >= '0') && (ch <= '9')); }
+inline bool IsDigitW(WCHAR wch) { return ((wch >= L'0') && (wch <= L'9')); }
 
 // Is the character a white space char?
-static inline bool IsBlankChar(CHAR ch) { return ((ch == ' ') || (ch == '\t')); }
-static inline bool IsBlankCharW(WCHAR wch) { return ((wch == L' ') || (wch == L'\t')); }
+inline bool IsBlankChar(CHAR ch) { return ((ch == ' ') || (ch == '\t')); }
+inline bool IsBlankCharW(WCHAR wch) { return ((wch == L' ') || (wch == L'\t')); }
 
 
-static inline int float2int(float f) { return (int)lroundf(f); }
-static inline float Round10th(float f) { return (float)float2int(f * 10.0f) / 10; }
-static inline bool HasNonZeroFraction(float f) { return ((float2int(f * 10.0f) % 10) != 0); }
+inline int float2int(float f) { return (int)lroundf(f); }
+inline float Round10th(float f) { return (float)float2int(f * 10.0f) / 10; }
+inline bool HasNonZeroFraction(float f) { return ((float2int(f * 10.0f) % 10) != 0); }
 
 
 // direct heap allocation
-static inline LPVOID AllocMem(size_t numBytes, DWORD dwFlags)
-{
+inline LPVOID AllocMem(size_t numBytes, DWORD dwFlags) {
   return HeapAlloc(GetProcessHeap(), (dwFlags | HEAP_GENERATE_EXCEPTIONS), numBytes);
 }
 
-static inline bool FreeMem(LPVOID lpMemory)
-{
+inline bool FreeMem(LPVOID lpMemory) {
   return ((lpMemory != NULL) ? HeapFree(GetProcessHeap(), 0, lpMemory) : true);
 }
 
-static inline size_t SizeOfMem(LPVOID lpMemory)
-{
+inline size_t SizeOfMem(LPVOID lpMemory) {
   return ((lpMemory != NULL) ? HeapSize(GetProcessHeap(), 0, lpMemory) : 0);
 }
 
@@ -113,7 +110,7 @@ static inline size_t SizeOfMem(LPVOID lpMemory)
 #define IniSetString(lpSection,lpName,lpString)                      WritePrivateProfileString(lpSection,lpName,(lpString),g_wchIniFile)
 #define IniDeleteSection(lpSection)                                  WritePrivateProfileSection(lpSection,NULL,g_wchIniFile)
 
-static inline bool IniSetInt(LPCWSTR lpSection, LPCWSTR lpName, int i) {
+inline bool IniSetInt(LPCWSTR lpSection, LPCWSTR lpName, int i) {
   WCHAR tch[32] = { L'\0' }; StringCchPrintf(tch, COUNTOF(tch), L"%i", i); return IniSetString(lpSection, lpName, tch);
 }
 
@@ -125,7 +122,7 @@ int IniSectionGetString(LPCWSTR, LPCWSTR, LPCWSTR, LPWSTR, int);
 int IniSectionGetInt(LPCWSTR, LPCWSTR, int);
 UINT IniSectionGetUInt(LPCWSTR, LPCWSTR, UINT);
 DocPos IniSectionGetPos(LPCWSTR, LPCWSTR, DocPos);
-static inline bool IniSectionGetBool(LPCWSTR lpCachedIniSection, LPCWSTR lpName, bool bDefault) {
+inline bool IniSectionGetBool(LPCWSTR lpCachedIniSection, LPCWSTR lpName, bool bDefault) {
   return (IniSectionGetInt(lpCachedIniSection, lpName, ((bDefault) ? 1 : 0)) ? true : false);
 }
 
@@ -137,14 +134,13 @@ inline bool IniSectionSetInt(LPWSTR lpCachedIniSection,LPCWSTR lpName, int i) {
 inline bool IniSectionSetBool(LPWSTR lpCachedIniSection, LPCWSTR lpName, bool b) {
   return IniSectionSetInt(lpCachedIniSection, lpName, (b ? 1 : 0));
 }
-inline bool IniSectionSetPos(LPWSTR lpCachedIniSection, LPCWSTR lpName, DocPos pos)
-{
+inline bool IniSectionSetPos(LPWSTR lpCachedIniSection, LPCWSTR lpName, DocPos pos){
   WCHAR tch[64] = { L'\0' }; StringCchPrintf(tch, COUNTOF(tch), L"%td", (long long)pos); return IniSectionSetString(lpCachedIniSection, lpName, tch);
 }
 
 // ----------------------------------------------------------------------------
 
-static inline COLORREF GetBackgroundColor(HWND hwnd) { return GetBkColor(GetDC(hwnd)); }
+inline COLORREF GetBackgroundColor(HWND hwnd) { return GetBkColor(GetDC(hwnd)); }
 
 DWORD GetLastErrorToMsgBox(LPWSTR lpszFunction, DWORD dwErrID);
 
@@ -259,7 +255,7 @@ DWORD GetLongPathNameEx(LPWSTR,DWORD);
 DWORD NormalizePathEx(LPWSTR,int);
 DWORD_PTR SHGetFileInfo2(LPCWSTR,DWORD,SHFILEINFO*,UINT,UINT);
 
-int  FormatNumberStr(LPWSTR);
+size_t FormatNumberStr(LPWSTR);
 bool SetDlgItemIntEx(HWND,int,UINT);
 
 
@@ -342,23 +338,16 @@ WCHAR* StrNextTokW(WCHAR*, const WCHAR*);
 
 // ----------------------------------------------------------------------------
 
-#define StrEndW(pStart) (pStart + lstrlen(pStart))
-#define StrEndA(pStart) (pStart + strlen(pStart))
-
-#if defined(UNICODE) || defined(_UNICODE)  
-#define StrEnd(s) StrEndW(s)
-#else
-#define StrEnd(s) StrEndA(s)
-#endif
-
-// ----------------------------------------------------------------------------
-
 bool StrDelChrA(LPSTR pszSource, LPCSTR pCharsToRemove);
 
 
 //==== StrSafe lstrlen() =======================================================
-inline DocPos StringCchLenA(LPCSTR s,size_t m) { size_t len; return (DocPos)(!s ? 0 : (SUCCEEDED(StringCchLengthA(s, m, &len)) ? len : m)); }
-inline DocPos StringCchLenW(LPCWSTR s,size_t m) { size_t len; return (DocPos)(!s ? 0 : (SUCCEEDED(StringCchLengthW(s, m, &len)) ? len : m)); }
+inline size_t StringCchLenA(LPCSTR s, size_t n) { 
+  size_t len; return (size_t)(!s ? 0 : (!n ? strlen(s) : (SUCCEEDED(StringCchLengthA(s, n, &len)) ? len : n)));
+}
+inline size_t StringCchLenW(LPCWSTR s, size_t n) { 
+  size_t len; return (size_t)(!s ? 0 : (!n ? lstrlen(s) : (SUCCEEDED(StringCchLengthW(s, n, &len)) ? len : n)));
+}
 
 #if defined(UNICODE) || defined(_UNICODE)  
 #define StringCchLen(s,n)  StringCchLenW((s),(n))
@@ -366,6 +355,23 @@ inline DocPos StringCchLenW(LPCWSTR s,size_t m) { size_t len; return (DocPos)(!s
 #define StringCchLen(s,n)  StringCchLenA((s),(n))
 #endif
 
+// ----------------------------------------------------------------------------
+
+inline char* StrEndA(const char* pStart, size_t siz) {
+  return (char*)(pStart + StringCchLenA(pStart, siz));
+}
+
+inline WCHAR* StrEndW(const WCHAR* pStart, size_t siz) {
+  return (WCHAR*)(pStart + StringCchLenW(pStart, siz));
+}
+
+#if defined(UNICODE) || defined(_UNICODE)  
+#define StrEnd(s,n) StrEndW((s),(n))
+#else
+#define StrEnd(s,n) StrEndA((s),(n))
+#endif
+
+
 //==== StrSafe lstrcmp(),lstrcmpi() =============================================
 inline int _StringCchCmpNA(PCNZCH s1, DocPos l1,PCNZCH s2, DocPos l2)
 {
@@ -383,7 +389,7 @@ inline int _StringCchCmpINA(PCNZCH s1, DocPos l1,PCNZCH s2, DocPos l2)
 #define StringCchCompareINA(s1,l1,s2,l2)  _StringCchCmpINA((s1),(l1),(s2),(l2))
 #define StringCchCompareIXA(s1,s2)        _StringCchCmpINA((s1),-1,(s2),-1)
 
-inline int _StringCchCmpNW(PCNZWCH s1, DocPos l1,PCNZWCH s2, DocPos l2) {
+inline int _StringCchCmpNW(PCNZWCH s1, DocPos l1, PCNZWCH s2, DocPos l2) {
   return (CompareStringW(LOCALE_INVARIANT,0,s1,(l1 >= 0 ? (int)StringCchLenW(s1,l1) : -1),
                          s2,(l2 >= 0 ? (int)StringCchLenW(s2,l2) : -1)) - CSTR_EQUAL);
 }
@@ -412,8 +418,8 @@ inline int _StringCchCmpINW(PCNZWCH s1, DocPos l1,PCNZWCH s2, DocPos l2) {
 
 //==== StrIs(Not)Empty() =============================================
 
-static inline bool StrIsEmptyA(LPCSTR s) { return ((s == NULL) || (*s == '\0')); }
-static inline bool StrIsEmptyW(LPCWSTR s) { return ((s == NULL) || (*s == L'\0')); }
+inline bool StrIsEmptyA(LPCSTR s) { return ((s == NULL) || (*s == '\0')); }
+inline bool StrIsEmptyW(LPCWSTR s) { return ((s == NULL) || (*s == L'\0')); }
 
 #if defined(UNICODE) || defined(_UNICODE)
 #define StrIsEmpty(s)     StrIsEmptyW(s)
diff --git a/src/Notepad3.c b/src/Notepad3.c
index 7c373b1ab..8537a34fd 100644
--- a/src/Notepad3.c
+++ b/src/Notepad3.c
@@ -302,8 +302,8 @@ int     yFindReplaceDlg;
 int     xCustomSchemesDlg;
 int     yCustomSchemesDlg;
 
-
-LPWSTR    lpFileList[32] = { NULL };
+#define FILE_LIST_SIZE 32
+LPWSTR    lpFileList[FILE_LIST_SIZE] = { NULL };
 int       cFileList = 0;
 int       cchiFileList = 0;
 LPWSTR    lpFileArg = NULL;
@@ -2506,7 +2506,7 @@ LRESULT MsgCopyData(HWND hwnd, WPARAM wParam, LPARAM lParam)
         if (params->flagLexerSpecified) {
           if (params->iInitialLexer < 0) {
             WCHAR wchExt[32] = L".";
-            StringCchCopyN(CharNext(wchExt), 32, StrEnd(&params->wchData) + 1, 31);
+            StringCchCopyN(CharNext(wchExt), 32, StrEnd(&params->wchData,0) + 1, 31);
             Style_SetLexerFromName(g_hwndEdit, &params->wchData, wchExt);
           }
           else if (params->iInitialLexer >= 0 && params->iInitialLexer < NUMLEXERS)
@@ -2514,7 +2514,7 @@ LRESULT MsgCopyData(HWND hwnd, WPARAM wParam, LPARAM lParam)
         }
 
         if (params->flagTitleExcerpt) {
-          StringCchCopyN(szTitleExcerpt, COUNTOF(szTitleExcerpt), StrEnd(&params->wchData) + 1, COUNTOF(szTitleExcerpt));
+          StringCchCopyN(szTitleExcerpt, COUNTOF(szTitleExcerpt), StrEnd(&params->wchData,0) + 1, COUNTOF(szTitleExcerpt));
         }
       }
       // reset
@@ -3042,7 +3042,7 @@ LRESULT MsgInitMenu(HWND hwnd, WPARAM wParam, LPARAM lParam)
   }
   EnableCmd(hmenu, CMD_OPEN_HYPERLINK, bIsHLink);
 
-  i = StringCchLenW(g_tchAdministrationExe, COUNTOF(g_tchAdministrationExe));
+  i = (int)StringCchLenW(g_tchAdministrationExe, COUNTOF(g_tchAdministrationExe));
   EnableCmd(hmenu, IDM_HELP_ADMINEXE, i);
 
   return 0LL;
@@ -5940,14 +5940,14 @@ void OpenHotSpotURL(DocPos position, bool bForceBrowser)
     MultiByteToWideCharStrg(Encoding_SciCP, chURL, wchURL);
 
     const WCHAR* chkPreFix = L"file://";
-    const int len = lstrlen(chkPreFix);
+    size_t const len = StringCchLenW(chkPreFix,0);
 
     if (!bForceBrowser && (StrStrIW(wchURL, chkPreFix) == wchURL))
     {
       WCHAR* szFileName = &(wchURL[len]);
       StrTrimW(szFileName, L"/");
 
-      PathCanonicalizeEx(szFileName, COUNTOF(wchURL) - len);
+      PathCanonicalizeEx(szFileName, COUNTOF(wchURL) - (int)len);
 
       if (PathIsDirectory(szFileName))
       {
@@ -6505,11 +6505,11 @@ LRESULT MsgNotify(HWND hwnd, WPARAM wParam, LPARAM lParam)
                   char chBuf[80];
                   if (g_iExprError == 0) {
                     StringCchPrintfA(chBuf, COUNTOF(chBuf), "%.6G", g_dExpression);
-                    SciCall_CopyText((DocPos)strlen(chBuf), chBuf);
+                    SciCall_CopyText((DocPos)StringCchLenA(chBuf,80), chBuf);
                   }
                   else if (g_iExprError > 0) {
                     StringCchPrintfA(chBuf, COUNTOF(chBuf), "^[%i]", g_iExprError);
-                    SciCall_CopyText((DocPos)strlen(chBuf), chBuf);
+                    SciCall_CopyText((DocPos)StringCchLenA(chBuf,80), chBuf);
                   }
                   else
                     SciCall_CopyText(0, "");
@@ -7227,15 +7227,15 @@ void ParseCommandLine()
   // Good old console can also send args separated by Tabs
   StrTab2Space(lpCmdLine);
 
-  int len = lstrlen(lpCmdLine) + 2;
+  DocPos const len = (DocPos)(StringCchLenW(lpCmdLine,0) + 2UL);
   lp1 = LocalAlloc(LPTR,sizeof(WCHAR)*len);
   lp2 = LocalAlloc(LPTR,sizeof(WCHAR)*len);
   lp3 = LocalAlloc(LPTR,sizeof(WCHAR)*len);
 
   // Start with 2nd argument
-  ExtractFirstArgument(lpCmdLine,lp1,lp3,len);
+  ExtractFirstArgument(lpCmdLine,lp1,lp3,(int)len);
 
-  while (bContinue && ExtractFirstArgument(lp3,lp1,lp2,len))
+  while (bContinue && ExtractFirstArgument(lp3,lp1,lp2,(int)len))
   {
     // options
     if (!bIsFileArg && (StringCchCompareN(lp1,len,L"+",-1) == 0)) {
@@ -7329,7 +7329,7 @@ void ParseCommandLine()
         case L'F':
           if (*(lp1+1) == L'0' || *CharUpper(lp1+1) == L'O')
             StringCchCopy(g_wchIniFile,COUNTOF(g_wchIniFile),L"*?");
-          else if (ExtractFirstArgument(lp2,lp1,lp2,len)) {
+          else if (ExtractFirstArgument(lp2,lp1,lp2,(int)len)) {
             StringCchCopyN(g_wchIniFile,COUNTOF(g_wchIniFile),lp1,len);
             TrimStringW(g_wchIniFile);
             PathUnquoteSpaces(g_wchIniFile);
@@ -7359,7 +7359,7 @@ void ParseCommandLine()
               lp += 1;
             else if (bIsNotepadReplacement) {
               if (*(lp1+1) == L'T')
-                ExtractFirstArgument(lp2,lp1,lp2,len);
+                ExtractFirstArgument(lp2,lp1,lp2,(int)len);
               break;
             }
             if (*(lp+1) == L'0' || *CharUpper(lp+1) == L'O') {
@@ -7405,7 +7405,7 @@ void ParseCommandLine()
                 p = CharNext(p);
               }
             }
-            else if (ExtractFirstArgument(lp2,lp1,lp2,len)) {
+            else if (ExtractFirstArgument(lp2,lp1,lp2,(int)len)) {
               int itok =
                 swscanf_s(lp1,L"%i,%i,%i,%i,%i",&g_WinInfo.x,&g_WinInfo.y,&g_WinInfo.cx,&g_WinInfo.cy,&g_WinInfo.max);
               if (itok == 4 || itok == 5) { // scan successful
@@ -7422,7 +7422,7 @@ void ParseCommandLine()
           break;
 
         case L'T':
-          if (ExtractFirstArgument(lp2,lp1,lp2,len)) {
+          if (ExtractFirstArgument(lp2,lp1,lp2,(int)len)) {
             StringCchCopyN(szTitleExcerpt,COUNTOF(szTitleExcerpt),lp1,len);
             fKeepTitleExcerpt = 1;
           }
@@ -7437,7 +7437,7 @@ void ParseCommandLine()
           break;
 
         case L'E':
-          if (ExtractFirstArgument(lp2,lp1,lp2,len)) {
+          if (ExtractFirstArgument(lp2,lp1,lp2,(int)len)) {
             if (lpEncodingArg)
               LocalFree(lpEncodingArg);
             lpEncodingArg = StrDup(lp1);
@@ -7445,7 +7445,7 @@ void ParseCommandLine()
           break;
 
         case L'G':
-          if (ExtractFirstArgument(lp2,lp1,lp2,len)) {
+          if (ExtractFirstArgument(lp2,lp1,lp2,(int)len)) {
             int itok =
               swscanf_s(lp1,L"%i,%i",&iInitialLine,&iInitialColumn);
             if (itok == 1 || itok == 2) { // scan successful
@@ -7467,7 +7467,7 @@ void ParseCommandLine()
             if (StrChr(lp1,L'B'))
               bTransBS = true;
 
-            if (ExtractFirstArgument(lp2,lp1,lp2,len)) {
+            if (ExtractFirstArgument(lp2,lp1,lp2,(int)len)) {
               if (lpMatchArg)
                 LocalFree(lpMatchArg);
               lpMatchArg = StrDup(lp1);
@@ -7501,7 +7501,7 @@ void ParseCommandLine()
           break;
 
         case L'S':
-          if (ExtractFirstArgument(lp2,lp1,lp2,len)) {
+          if (ExtractFirstArgument(lp2,lp1,lp2,(int)len)) {
             if (lpSchemeArg)
               LocalFree(lpSchemeArg);
             lpSchemeArg = StrDup(lp1);
@@ -7541,7 +7541,7 @@ void ParseCommandLine()
           break;
 
         case L'Z':
-          ExtractFirstArgument(lp2,lp1,lp2,len);
+          ExtractFirstArgument(lp2,lp1,lp2,(int)len);
           g_flagMultiFileArg = 1;
           bIsNotepadReplacement = true;
           break;
@@ -7568,7 +7568,7 @@ void ParseCommandLine()
     {
       LPWSTR lpFileBuf = LocalAlloc(LPTR,sizeof(WCHAR)*len);
 
-      cchiFileList = lstrlen(lpCmdLine) - lstrlen(lp3);
+      cchiFileList = (int)(StringCchLenW(lpCmdLine, len-2) - StringCchLenW(lp3,len));
 
       if (lpFileArg) {
         FreeMem(lpFileArg);
@@ -7591,7 +7591,7 @@ void ParseCommandLine()
 
       StrTrim(lpFileArg,L" \"");
 
-      while (cFileList < 32 && ExtractFirstArgument(lp3,lpFileBuf,lp3,len)) {
+      while ((cFileList < FILE_LIST_SIZE) && ExtractFirstArgument(lp3,lpFileBuf,lp3,(int)len)) {
         PathQuoteSpaces(lpFileBuf);
         lpFileList[cFileList++] = StrDup(lpFileBuf);
       }
@@ -7819,7 +7819,7 @@ int TestIniFile() {
     return(0);
   }
 
-  if (PathIsDirectory(g_wchIniFile) || *CharPrev(g_wchIniFile,StrEnd(g_wchIniFile)) == L'\\') {
+  if (PathIsDirectory(g_wchIniFile) || *CharPrev(g_wchIniFile,StrEnd(g_wchIniFile, COUNTOF(g_wchIniFile))) == L'\\') {
     WCHAR wchModule[MAX_PATH] = { L'\0' };
     GetModuleFileName(NULL,wchModule,COUNTOF(wchModule));
     PathCchAppend(g_wchIniFile,COUNTOF(g_wchIniFile),PathFindFileName(wchModule));
@@ -7981,7 +7981,7 @@ static void __fastcall _UpdateToolbarDelayed()
 
   EnableTool(IDT_EDIT_FIND, b2);
   //EnableTool(IDT_EDIT_FINDNEXT,b2);
-  //EnableTool(IDT_EDIT_FINDPREV,b2 && strlen(g_efrData.szFind));
+  //EnableTool(IDT_EDIT_FINDPREV,b2 && StringCchLenA(g_efrData.szFind,0));
   EnableTool(IDT_EDIT_REPLACE, b2 && !ro);
 
   EnableTool(IDT_EDIT_CUT, !b1 && !ro);
@@ -8008,7 +8008,7 @@ static LONG __fastcall _StatusCalcPaneWidth(HWND hwnd, LPCWSTR lpsz)
   int const mmode = SetMapMode(hdc, MM_TEXT);
 
   SIZE size = { 0L, 0L };
-  GetTextExtentPoint32(hdc, lpsz, lstrlen(lpsz), &size);
+  GetTextExtentPoint32(hdc, lpsz, (int)StringCchLenW(lpsz,0), &size);
 
   SetMapMode(hdc, mmode);
   SelectObject(hdc, hfold);
@@ -8177,10 +8177,10 @@ static double __fastcall _InterpRectSelTinyExpr(int* piExprError)
 
     if (!StrIsEmptyA(tmpRectSelN))
     {
-      if (IsDigit(tmpRectSelN[0]) && bLastCharWasDigit) {
+      if (IsDigitA(tmpRectSelN[0]) && bLastCharWasDigit) {
         StringCchCatA(g_pTempLineBufferMain, tmpLineBufSize, "+"); // default: add numbers
       }
-      bLastCharWasDigit = IsDigit(tmpRectSelN[strlen(tmpRectSelN) - 1]);
+      bLastCharWasDigit = IsDigitA(tmpRectSelN[StringCchLenA(tmpRectSelN,COUNTOF(tmpRectSelN)) - 1]);
       StringCchCatA(g_pTempLineBufferMain, tmpLineBufSize, tmpRectSelN);
     }
   }
@@ -9527,10 +9527,10 @@ bool FileSave(bool bSaveAlways,bool bAsk,bool bSaveAs,bool bSaveCopy)
             //~Encoding_Current(fileEncoding); // save should not change encoding
             WCHAR szArguments[2048] = { L'\0' };
             LPWSTR lpCmdLine = GetCommandLine();
-            int wlen = lstrlen(lpCmdLine) + 2;
+            size_t const wlen = StringCchLenW(lpCmdLine,0) + 2;
             LPWSTR lpExe = LocalAlloc(LPTR,sizeof(WCHAR)*wlen);
             LPWSTR lpArgs = LocalAlloc(LPTR,sizeof(WCHAR)*wlen);
-            ExtractFirstArgument(lpCmdLine,lpExe,lpArgs,wlen);
+            ExtractFirstArgument(lpCmdLine,lpExe,lpArgs,(int)wlen);
             // remove relaunch elevated, we are doing this here already
             lpArgs = StrCutI(lpArgs,L"/u ");
             lpArgs = StrCutI(lpArgs,L"-u ");
@@ -9796,17 +9796,17 @@ bool ActivatePrevInst()
 
         SetForegroundWindow(hwnd);
 
-        DWORD cb = sizeof(np3params);
-        if (lpSchemeArg)
-          cb += (lstrlen(lpSchemeArg) + 1) * sizeof(WCHAR);
-
+        size_t cb = sizeof(np3params);
+        if (lpSchemeArg) {
+          cb += ((StringCchLen(lpSchemeArg, 0) + 1) * sizeof(WCHAR));
+        }
         LPnp3params params = AllocMem(cb, HEAP_ZERO_MEMORY);
         params->flagFileSpecified = false;
         params->flagChangeNotify = 0;
         params->flagQuietCreate = false;
         params->flagLexerSpecified = g_flagLexerSpecified;
         if (g_flagLexerSpecified && lpSchemeArg) {
-          StringCchCopy(StrEnd(&params->wchData)+1,(lstrlen(lpSchemeArg)+1),lpSchemeArg);
+          StringCchCopy(StrEnd(&params->wchData,0)+1,(StringCchLen(lpSchemeArg,0)+1),lpSchemeArg);
           params->iInitialLexer = -1;
         }
         else
@@ -9890,24 +9890,24 @@ bool ActivatePrevInst()
           StringCchCopy(lpFileArg, FILE_ARG_BUF, tchTmp);
         }
 
-        DWORD cb = sizeof(np3params);
-        cb += (lstrlen(lpFileArg) + 1) * sizeof(WCHAR);
+        size_t cb = sizeof(np3params);
+        cb += (StringCchLenW(lpFileArg,0) + 1) * sizeof(WCHAR);
 
         if (lpSchemeArg)
-          cb += (lstrlen(lpSchemeArg) + 1) * sizeof(WCHAR);
+          cb += (StringCchLenW(lpSchemeArg,0) + 1) * sizeof(WCHAR);
 
-        int cchTitleExcerpt = (int)StringCchLenW(szTitleExcerpt,COUNTOF(szTitleExcerpt));
+        size_t cchTitleExcerpt = StringCchLenW(szTitleExcerpt,COUNTOF(szTitleExcerpt));
         if (cchTitleExcerpt) {
           cb += (cchTitleExcerpt + 1) * sizeof(WCHAR);
         }
         LPnp3params params = AllocMem(cb, HEAP_ZERO_MEMORY);
         params->flagFileSpecified = true;
-        StringCchCopy(&params->wchData,lstrlen(lpFileArg)+1,lpFileArg);
+        StringCchCopy(&params->wchData, StringCchLenW(lpFileArg,0)+1,lpFileArg);
         params->flagChangeNotify = g_flagChangeNotify;
         params->flagQuietCreate = g_flagQuietCreate;
         params->flagLexerSpecified = g_flagLexerSpecified;
         if (g_flagLexerSpecified && lpSchemeArg) {
-          StringCchCopy(StrEnd(&params->wchData)+1,lstrlen(lpSchemeArg)+1,lpSchemeArg);
+          StringCchCopy(StrEnd(&params->wchData,0)+1, StringCchLen(lpSchemeArg,0)+1,lpSchemeArg);
           params->iInitialLexer = -1;
         }
         else {
@@ -9922,7 +9922,7 @@ bool ActivatePrevInst()
         params->flagSetEOLMode = g_flagSetEOLMode;
 
         if (cchTitleExcerpt) {
-          StringCchCopy(StrEnd(&params->wchData)+1,cchTitleExcerpt+1,szTitleExcerpt);
+          StringCchCopy(StrEnd(&params->wchData,0)+1,cchTitleExcerpt+1,szTitleExcerpt);
           params->flagTitleExcerpt = 1;
         }
         else {
@@ -9964,14 +9964,14 @@ bool RelaunchMultiInst() {
     PROCESS_INFORMATION pi;
 
     LPWSTR lpCmdLineNew = StrDup(GetCommandLine());
-    int len = lstrlen(lpCmdLineNew) + 1;
+    size_t len = StringCchLen(lpCmdLineNew,0) + 1UL;
     LPWSTR lp1 = LocalAlloc(LPTR,sizeof(WCHAR)*len);
     LPWSTR lp2 = LocalAlloc(LPTR,sizeof(WCHAR)*len);
 
     StrTab2Space(lpCmdLineNew);
     StringCchCopy(lpCmdLineNew + cchiFileList,2,L"");
 
-    pwch = CharPrev(lpCmdLineNew,StrEnd(lpCmdLineNew));
+    pwch = CharPrev(lpCmdLineNew,StrEnd(lpCmdLineNew,len));
     while (*pwch == L' ' || *pwch == L'-' || *pwch == L'+') {
       *pwch = L' ';
       pwch = CharPrev(lpCmdLineNew,pwch);
@@ -10027,13 +10027,13 @@ bool RelaunchElevated(LPWSTR lpArgs) {
   GetStartupInfo(&si);
 
   LPWSTR lpCmdLine = GetCommandLine();
-  int wlen = lstrlen(lpCmdLine) + 2;
+  size_t wlen = StringCchLenW(lpCmdLine,0) + 2UL;
 
   WCHAR lpExe[MAX_PATH + 2] = { L'\0' };
   WCHAR szArgs[2032] = { L'\0' };
   WCHAR szArguments[2032] = { L'\0' };
 
-  ExtractFirstArgument(lpCmdLine,lpExe,szArgs,wlen);
+  ExtractFirstArgument(lpCmdLine,lpExe,szArgs,(int)wlen);
 
   if (lpArgs) {
     StringCchCopy(szArgs,COUNTOF(szArgs),lpArgs); // override
diff --git a/src/Print.cpp b/src/Print.cpp
index 5ba50e131..d824c8e19 100644
--- a/src/Print.cpp
+++ b/src/Print.cpp
@@ -377,7 +377,7 @@ extern "C" bool EditPrint(HWND hwnd,LPCWSTR pszDocTitle,LPCWSTR pszPageFormat)
       {
         ExtTextOut(hdc, frPrint.rc.left + 5, frPrint.rc.top - headerLineHeight / 2,
                       /*ETO_OPAQUE*/0, &rcw, pszDocTitle,
-                      lstrlen(pszDocTitle), nullptr);
+                   (UINT)StringCchLenW(pszDocTitle,0), nullptr);
       }
 
       // Print date in header
diff --git a/src/Styles.c b/src/Styles.c
index 2bd580c53..db45eddd4 100644
--- a/src/Styles.c
+++ b/src/Styles.c
@@ -4319,7 +4319,7 @@ PEDITLEXER __fastcall Style_MatchLexer(LPCWSTR lpszMatch,bool bCheckNames) {
         if (p2)
           *p2 = L'\0';
         else
-          p2 = StrEnd(p1);
+          p2 = StrEnd(p1,0);
         StrTrim(p1,L" .");
         if (StringCchCompareIX(p1,lpszMatch) == 0)
           return(g_pLexArray[i]);
@@ -4328,7 +4328,7 @@ PEDITLEXER __fastcall Style_MatchLexer(LPCWSTR lpszMatch,bool bCheckNames) {
     }
   }
   else {
-    int cch = lstrlen(lpszMatch);
+    int cch = (int)StringCchLenW(lpszMatch,0);
     if (cch >= 3) {
       for (i = 0; i < COUNTOF(g_pLexArray); i++) {
         if (StrCmpNI(g_pLexArray[i]->pszName,lpszMatch,cch) == 0)
@@ -4947,7 +4947,7 @@ bool Style_StrGetColor(bool bFore, LPCWSTR lpszStyle, COLORREF* rgb)
   WCHAR *p = StrStrI(lpszStyle, pItem);
   if (p)
   {
-    StringCchCopy(tch, COUNTOF(tch), p + lstrlen(pItem));
+    StringCchCopy(tch, COUNTOF(tch), p + StringCchLenW(pItem,0));
     if (tch[0] == L'#')
       tch[0] = L' ';
     p = StrChr(tch, L';');
@@ -4977,7 +4977,7 @@ bool Style_StrGetAlpha(LPCWSTR lpszStyle, int* i, bool bAlpha1st)
   WCHAR* p = StrStrI(lpszStyle, strAlpha);
   if (p) {
     WCHAR tch[BUFSIZE_STYLE_VALUE] = { L'\0' };
-    StringCchCopy(tch, COUNTOF(tch), p + lstrlen(strAlpha));
+    StringCchCopy(tch, COUNTOF(tch), p + StringCchLenW(strAlpha,0));
     p = StrChr(tch, L';');
     if (p)
       *p = L'\0';
@@ -5002,7 +5002,7 @@ bool Style_StrGetAlpha(LPCWSTR lpszStyle, int* i, bool bAlpha1st)
 //  WCHAR tch[BUFSIZE_STYLE_VALUE] = { L'\0' };
 //  WCHAR *p = StrStrI(lpszStyle, lpszProperty);
 //  if (p) {
-//    StringCchCopy(tch, COUNTOF(tch), (p + lstrlen(lpszProperty)));
+//    StringCchCopy(tch, COUNTOF(tch), (p + StringCchLenW(lpszProperty,0)));
 //    p = StrChr(tch, L';');
 //    if (p)
 //      *p = L'\0';