diff --git a/static/js/narrow.js b/static/js/narrow.js
index 367254fa41..aa392d8ada 100644
--- a/static/js/narrow.js
+++ b/static/js/narrow.js
@@ -73,7 +73,7 @@ exports.unparse = function (operators) {
             // a colon are glued together to form a search term.
             return elem[1];
         } else {
-            return elem[0] + ':' + encodeOperand(elem[1].toString().toLowerCase());
+            return elem[0] + ':' + encodeOperand(elem[1]);
         }
     });
     return parts.join(' ');
diff --git a/zerver/tests/frontend/node/narrow.js b/zerver/tests/frontend/node/narrow.js
index 0f543010bb..59cbd432f2 100644
--- a/zerver/tests/frontend/node/narrow.js
+++ b/zerver/tests/frontend/node/narrow.js
@@ -19,7 +19,7 @@ var stream_data = global.stream_data;
 
     assert.deepEqual(narrow.parse(string), operators);
 
-    string = 'stream:foo topic:bar yo';
+    string = 'stream:Foo topic:Bar yo';
     assert.deepEqual(narrow.unparse(operators), string);
 }());