diff --git a/test/test-config-parse-logsize.c b/test/test-config-parse-logsize.c
index 4946cf0..7afbd1c 100644
--- a/test/test-config-parse-logsize.c
+++ b/test/test-config-parse-logsize.c
@@ -53,7 +53,7 @@
 			     test_data[i].test_str, test_data[i].expected_rc,
 			     rc);
 		} else if (rc == 0 && test_data[i].expected_size != size) {
-			warn("[%zu] Str %s expected size %lu, got size %lu\n",
+			warn("[%zu] Str %s expected size %zu, got size %zu\n",
 			     i, test_data[i].test_str,
 			     test_data[i].expected_size, size);
 		}