diff --git a/tests/api/test-check-require-stack-top.c b/tests/api/test-check-require-stack-top.c
index afe6231b..e2af9d32 100644
--- a/tests/api/test-check-require-stack-top.c
+++ b/tests/api/test-check-require-stack-top.c
@@ -136,7 +136,6 @@ static duk_ret_t require_1_inner(duk_context *ctx) {
 }
 static duk_ret_t require_1(duk_context *ctx, void *udata) {
 	int i;
-	duk_ret_t rc;
 
 	(void) udata;
 
diff --git a/tests/api/test-pcall-prop-obj-is-key.c b/tests/api/test-pcall-prop-obj-is-key.c
index 7c485d16..42396979 100644
--- a/tests/api/test-pcall-prop-obj-is-key.c
+++ b/tests/api/test-pcall-prop-obj-is-key.c
@@ -28,6 +28,8 @@ final top: 1
 static duk_ret_t test_obj_is_key(duk_context *ctx, void *udata) {
 	duk_int_t rc;
 
+	(void) udata;
+
 	duk_eval_string(ctx,
 		"({\n"
 		"    toString: function () { print('toString() called'); return 'myProp' },\n"
@@ -58,6 +60,8 @@ static duk_ret_t test_obj_is_key(duk_context *ctx, void *udata) {
 static duk_ret_t test_obj_is_arg(duk_context *ctx, void *udata) {
 	duk_int_t rc;
 
+	(void) udata;
+
 	duk_push_string(ctx, "myProp");
 
 	duk_eval_string(ctx,
diff --git a/tests/api/test-safe-call-invalid-nargs.c b/tests/api/test-safe-call-invalid-nargs.c
index 14b704d6..cfe6750e 100644
--- a/tests/api/test-safe-call-invalid-nargs.c
+++ b/tests/api/test-safe-call-invalid-nargs.c
@@ -20,6 +20,8 @@ static duk_ret_t dummy(duk_context *ctx, void *udata) {
 static duk_ret_t test_nargs_too_large(duk_context *ctx, void *udata) {
 	duk_int_t rc;
 
+	(void) udata;
+
 	duk_push_null(ctx);
 	duk_push_null(ctx);
 	duk_push_null(ctx);
@@ -35,6 +37,8 @@ static duk_ret_t test_nargs_too_large(duk_context *ctx, void *udata) {
 static duk_ret_t test_nargs_minus1(duk_context *ctx, void *udata) {
 	duk_int_t rc;
 
+	(void) udata;
+
 	duk_push_null(ctx);
 	duk_push_null(ctx);
 	duk_push_null(ctx);
diff --git a/tests/api/test-safe-call-invalid-nrets.c b/tests/api/test-safe-call-invalid-nrets.c
index 29649d5e..1a83ed7e 100644
--- a/tests/api/test-safe-call-invalid-nrets.c
+++ b/tests/api/test-safe-call-invalid-nrets.c
@@ -25,6 +25,8 @@ static duk_ret_t dummy(duk_context *ctx, void *udata) {
 static duk_ret_t test_nrets_too_large(duk_context *ctx, void *udata) {
 	duk_int_t rc;
 
+	(void) udata;
+
 	duk_push_null(ctx);
 	duk_push_null(ctx);
 	duk_push_null(ctx);
@@ -44,6 +46,8 @@ static duk_ret_t test_nrets_too_large(duk_context *ctx, void *udata) {
 static duk_ret_t test_nrets_too_large_fixed(duk_context *ctx, void *udata) {
 	duk_int_t rc;
 
+	(void) udata;
+
 	duk_push_null(ctx);
 	duk_push_null(ctx);
 	duk_push_null(ctx);
@@ -64,6 +68,8 @@ static duk_ret_t test_nrets_too_large_fixed(duk_context *ctx, void *udata) {
 static duk_ret_t test_nrets_minus1(duk_context *ctx, void *udata) {
 	duk_int_t rc;
 
+	(void) udata;
+
 	duk_push_null(ctx);
 	duk_push_null(ctx);
 	duk_push_null(ctx);