diff --git a/trace.graphqls b/trace.graphqls
index 8f359c7974d3a23afb443d6a228ea1fd62eacb41..8f24d5a7ca6088db40c5164c6417ac61abfd123d 100644
--- a/trace.graphqls
+++ b/trace.graphqls
@@ -33,7 +33,7 @@ type BasicTrace {
 # Represent the conditions used for query TraceBrief
 input TraceQueryCondition {
     # The value of 0 means all services.
-    serviceId: Int
+    serviceId: ID
     traceId: String
     endpointId: ID
     endpointName: String