diff --git a/src/shared/Util/Util.h b/src/shared/Util/Util.h
index 4a0fcf89d6..80b43dd43c 100644
--- a/src/shared/Util/Util.h
+++ b/src/shared/Util/Util.h
@@ -310,12 +310,12 @@ inline bool isEastAsianString(const std::wstring& wstr, bool numericOrSpace)
 
 inline void strToUpper(std::string& str)
 {
-    std::transform(str.begin(), str.end(), str.begin(), toupper);
+    std::transform(str.begin(), str.end(), str.begin(), ::toupper);
 }
 
 inline void strToLower(std::string& str)
 {
-    std::transform(str.begin(), str.end(), str.begin(), tolower);
+    std::transform(str.begin(), str.end(), str.begin(), ::tolower);
 }
 
 inline wchar_t wcharToUpper(wchar_t wchar)