diff --git a/skeletons/tests/check-INTEGER.c b/skeletons/tests/check-INTEGER.c
index 4ec9fd5..8c4496c 100644
--- a/skeletons/tests/check-INTEGER.c
+++ b/skeletons/tests/check-INTEGER.c
@@ -14,7 +14,7 @@
 }
 
 static void
-check(uint8_t *buf, int size, long check_long, int check_ret) {
+check(uint8_t *buf, size_t size, long check_long, int check_ret) {
 	char scratch[128];
 	char verify[32];
 	INTEGER_t val;