diff --git a/encoding/openapi/openapi_test.go b/encoding/openapi/openapi_test.go
index 9fbe314..bcdaf19 100644
--- a/encoding/openapi/openapi_test.go
+++ b/encoding/openapi/openapi_test.go
@@ -63,6 +63,10 @@
 		"nums.json",
 		defaultConfig,
 	}, {
+		"builtins.cue",
+		"builtins.json",
+		defaultConfig,
+	}, {
 		"oneof.cue",
 		"oneof.json",
 		defaultConfig,