diff --git a/git-compat-util.h b/git-compat-util.h
index 041cbdb93..f1fa9e611 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -374,9 +374,15 @@ extern FILE *git_fopen(const char*, const char*);
 #endif
 
 #ifdef SNPRINTF_RETURNS_BOGUS
+#ifdef snprintf
+#undef snprintf
+#endif
 #define snprintf git_snprintf
 extern int git_snprintf(char *str, size_t maxsize,
 			const char *format, ...);
+#ifdef vsnprintf
+#undef vsnprintf
+#endif
 #define vsnprintf git_vsnprintf
 extern int git_vsnprintf(char *str, size_t maxsize,
 			 const char *format, va_list ap);