diff --git a/test/moduletest/param_test_cmds.c b/test/moduletest/param_test_cmds.c
index c5d51106f015690920add99c727a2d984613c3a8..a61f76f9ee838c7a4cfb941bd4b8ed848d7a82bd 100644
--- a/test/moduletest/param_test_cmds.c
+++ b/test/moduletest/param_test_cmds.c
@@ -88,7 +88,7 @@ static int32_t BShellParamCmdWatch(BShellHandle shell, int32_t argc, char *argv[
 {
     PLUGIN_CHECK(argc >= 1, return -1, "Invalid parameter");
     PLUGIN_LOGV("BShellParamCmdWatch %s", argv[1]);
-    static int index = 0;
+    static size_t index = 0;
     int ret = SystemWatchParameter(argv[1], HandleParamChange, (void *)index);
     if (ret != 0) {
         PLUGIN_LOGE("Failed to watch %s", argv[1]);