diff --git a/pkg/sync/runtime_exectracer2.go b/pkg/sync/runtime_exectracer2.go
index 4ec3baf97..f6094cab6 100644
--- a/pkg/sync/runtime_exectracer2.go
+++ b/pkg/sync/runtime_exectracer2.go
@@ -19,5 +19,5 @@ package sync
 // TraceBlockReason constants, from Go's src/runtime/trace2runtime.go.
 const (
 	TraceBlockSelect TraceBlockReason = 3 // +checkconst runtime traceBlockSelect
-	TraceBlockSync                    = 5 // +checkconst runtime traceBlockSync
+	TraceBlockSync   TraceBlockReason = 5 // +checkconst runtime traceBlockSync
 )