diff --git a/include/m_string.h b/include/m_string.h
index d7086555b1e..8b23d765e91 100644
--- a/include/m_string.h
+++ b/include/m_string.h
@@ -243,7 +243,7 @@ longlong my_strtoll10(const char *nptr, char **endptr, int *error);
 #ifdef HAVE_LONG_LONG
 extern char *longlong2str(longlong val,char *dst,int radix);
 extern char *longlong10_to_str(longlong val,char *dst,int radix);
-#if (!defined(HAVE_STRTOULL) || defined(NO_STRTOLL_PROTO)
+#if (!defined(HAVE_STRTOULL) || defined(NO_STRTOLL_PROTO))
 extern longlong strtoll(const char *str, char **ptr, int base);
 extern ulonglong strtoull(const char *str, char **ptr, int base);
 #endif