diff --git a/sync.m b/sync.m
index 1f4a4aa..07e8890 100644
--- a/sync.m
+++ b/sync.m
@@ -4,6 +4,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+int snprintf(char *restrict s, size_t n, const char *restrict format, ...);
+
+
 @interface Fake
 + (void)dealloc;
 @end