diff --git a/cmd/protogen/main.go b/cmd/protogen/main.go
index 08babfdc..572332b0 100644
--- a/cmd/protogen/main.go
+++ b/cmd/protogen/main.go
@@ -138,7 +138,7 @@ func runProtoc(ctx context.Context, cfg genConfig, protoDirs []string) error {
 
 	for i := 0; i < len(protoDirs); i++ {
 		dir := protoDirs[i]
-		files, err := filepath.Glob(filepath.Join(dir, "*"))
+		files, err := filepath.Glob(filepath.Join(dir, "*.proto"))
 		if err != nil {
 			return err
 		}