diff --git a/extractor.go b/extractor.go
index 8b3ed4f..875bb1c 100644
--- a/extractor.go
+++ b/extractor.go
@@ -94,6 +94,7 @@ func extractEndpoint(method reflect.Method) *registry.Endpoint {
 		Name:     method.Name,
 		Request:  request,
 		Response: response,
+		Metadata: make(map[string]string),
 	}
 
 	if stream {