--- a/toolkit/components/find/nsFind.cpp
+++ b/toolkit/components/find/nsFind.cpp
@@ -27,17 +27,17 @@
 #include "nsRange.h"
 #include "nsContentUtils.h"
 #include "mozilla/DebugOnly.h"
 #include "mozilla/TextEditor.h"
 
 using namespace mozilla;
 
 // Yikes!  Casting a char to unichar can fill with ones!
-#define CHAR_TO_UNICHAR(c) ((char16_t)(const unsigned char)c)
+#define CHAR_TO_UNICHAR(c) ((char16_t)(unsigned char)c)
 
 static NS_DEFINE_CID(kCContentIteratorCID, NS_CONTENTITERATOR_CID);
 static NS_DEFINE_CID(kCPreContentIteratorCID, NS_PRECONTENTITERATOR_CID);
 
 #define CH_QUOTE ((char16_t)0x22)
 #define CH_APOSTROPHE ((char16_t)0x27)
 #define CH_LEFT_SINGLE_QUOTE ((char16_t)0x2018)
 #define CH_RIGHT_SINGLE_QUOTE ((char16_t)0x2019)