diff --git a/writer/source_gcs.go b/writer/source_gcs.go
index 2124978fe9fe3878add17c851fb8a46ed8f8242c..a810b0a58cf88142161e88ec315af8be20b2ab91 100644
--- a/writer/source_gcs.go
+++ b/writer/source_gcs.go
@@ -1,3 +1,5 @@
+//go:build gcs
+
 package writer
 
 import (
diff --git a/writer/source_s3.go b/writer/source_s3.go
index bf6cfdf1e27505408f60031eaee0da6464929787..04b3fa77ab51e1120718cf9fb223e9cd6a7a9118 100644
--- a/writer/source_s3.go
+++ b/writer/source_s3.go
@@ -1,3 +1,5 @@
+//go:build s3
+
 package writer
 
 import (