diff --git a/ext/standard/crypt_sha256.c b/ext/standard/crypt_sha256.c
index 826b4d1593e..ee68cec0275 100644
--- a/ext/standard/crypt_sha256.c
+++ b/ext/standard/crypt_sha256.c
@@ -520,7 +520,7 @@ char * php_sha256_crypt_r(const char *key, const char *salt, char *buffer, int b
 
 	if (rounds_custom) {
 #ifdef PHP_WIN32
-		int n = _snprintf(cp, MAX(0, buflen), "%s%u$", sha256_rounds_prefix, rounds);
+		int n = _snprintf(cp, MAX(0, buflen), "%s%I64u$", sha256_rounds_prefix, rounds);
 #else
 		int n = snprintf(cp, MAX(0, buflen), "%s%zu$", sha256_rounds_prefix, rounds);
 #endif