diff --git a/glslang/Include/Common.h b/glslang/Include/Common.h
index e5c18b99..05c8447f 100644
--- a/glslang/Include/Common.h
+++ b/glslang/Include/Common.h
@@ -63,7 +63,7 @@ std::string to_string(const T& val) {
 }
 #endif
 
-#if _MSC_VER < 1700
+#if defined(_MSC_VER) && _MSC_VER < 1700
 inline long long int strtoll (const char* str, char** endptr, int base)
 {
   return _strtoi64(str, endptr, base);