diff --git a/scionigmo/OnigmoRegExEngine.cxx b/scionigmo/OnigmoRegExEngine.cxx
index f295953fb..d7c5060c4 100644
--- a/scionigmo/OnigmoRegExEngine.cxx
+++ b/scionigmo/OnigmoRegExEngine.cxx
@@ -59,7 +59,7 @@ using namespace Scintilla;
 // ***   Oningmo configuration   ***
 // ============================================================================
 
-const OnigEncoding g_pOnigEncodingType = ONIG_ENCODING_UTF8;  // ONIG_ENCODING_ASCII;
+constexpr OnigEncoding g_pOnigEncodingType = ONIG_ENCODING_UTF8;  // ONIG_ENCODING_ASCII;
 static OnigEncoding g_UsedEncodingsTypes[] = { g_pOnigEncodingType };
 
 // ============================================================================
@@ -147,16 +147,16 @@ RegexSearchBase *Scintilla::CreateRegexSearch(CharClassify *charClassTable)
 *
 * Is the character an octal digit?
 */
-inline bool IsOctalDigit(char ch)
+constexpr bool IsOctalDigit(char ch)
 {
   return ((ch >= '0') && (ch <= '7'));
 }
 // ----------------------------------------------------------------------------
 
 /**
-* If the character is an hexa digit, get its value.
+* If the character is an hex digit, get its value.
 */
-inline int GetHexDigit(char ch)
+constexpr int GetHexDigit(char ch)
 {
   if ((ch >= '0') && (ch <= '9')) {
     return (ch - '0');
diff --git a/src/EncodingCED.cpp b/src/EncodingCED.cpp
index 3b6ff9df7..e4d11efba 100644
--- a/src/EncodingCED.cpp
+++ b/src/EncodingCED.cpp
@@ -291,7 +291,7 @@ extern "C" int Encoding_CountOf()
 
 // ============================================================================
 
-static int  MapCPI2Encoding(const int iNP3Encoding)
+constexpr int MapCPI2Encoding(const int iNP3Encoding)
 {
   if ((iNP3Encoding < 0) || (iNP3Encoding >= Encoding_CountOf())) {
     return UNKNOWN_ENCODING; // CPI_NONE, CPI_GET
@@ -305,7 +305,7 @@ static int  MapCPI2Encoding(const int iNP3Encoding)
 
 
 
-static int  FindCodePage(const Encoding& encoding)
+constexpr int FindCodePage(const Encoding& encoding)
 {
   int iCodePage = -1;