diff --git a/build/manifest/main.go b/build/manifest/main.go
index c5eb60c0..9d878c96 100644
--- a/build/manifest/main.go
+++ b/build/manifest/main.go
@@ -127,7 +127,7 @@ func applyManifest(manifest *model.Manifest) error {
 		if err := ioutil.WriteFile(
 			"server/manifest.go",
 			[]byte(fmt.Sprintf(pluginIDGoFileTemplate, manifestStr)),
-			0644,
+			0600,
 		); err != nil {
 			return errors.Wrap(err, "failed to write server/manifest.go")
 		}
@@ -147,7 +147,7 @@ func applyManifest(manifest *model.Manifest) error {
 		if err := ioutil.WriteFile(
 			"webapp/src/manifest.js",
 			[]byte(fmt.Sprintf(pluginIDJSFileTemplate, manifestStr)),
-			0644,
+			0600,
 		); err != nil {
 			return errors.Wrap(err, "failed to open webapp/src/manifest.js")
 		}