diff --git a/libc/stdio/vsprintf.c b/libc/stdio/vsprintf.c
index 67a53a1..846ee8a 100644
--- a/libc/stdio/vsprintf.c
+++ b/libc/stdio/vsprintf.c
@@ -53,7 +53,7 @@
 	f._flags = __SWR | __SSTR;
 	f._bf._base = f._p = (unsigned char *)str;
 	f._bf._size = f._w = INT_MAX;
-	ret = vfprintf(&f, fmt, ap);
+	ret = __vfprintf(&f, fmt, ap);
 	*f._p = '\0';
 	return (ret);
 }