diff --git a/mingw-w64-crt/stdio/_vscprintf.c b/mingw-w64-crt/stdio/_vscprintf.c
index b859b9a..bb596b4 100644
--- a/mingw-w64-crt/stdio/_vscprintf.c
+++ b/mingw-w64-crt/stdio/_vscprintf.c
@@ -15,7 +15,7 @@
 {
     char *buffer, *new_buffer;
     size_t size;
-    int ret;
+    int ret = -1;
 
     /* if format is a null pointer, _vscprintf() returns -1 and sets errno to EINVAL */
     if (!format) {