diff --git a/cmd/gobind/gen.go b/cmd/gobind/gen.go
index ce2bc5d..fedbc27 100644
--- a/cmd/gobind/gen.go
+++ b/cmd/gobind/gen.go
@@ -376,10 +376,14 @@
 }
 
 func packageDir(path string) (string, error) {
-	pkgs, err := packages.Load(nil, path)
+	mode := packages.NeedFiles
+	pkgs, err := packages.Load(&packages.Config{Mode: mode}, path)
 	if err != nil {
 		return "", err
 	}
+	if len(pkgs) == 0 || len(pkgs[0].GoFiles) == 0 {
+		return "", fmt.Errorf("no Go package in %v", path)
+	}
 	pkg := pkgs[0]
 	if len(pkg.Errors) > 0 {
 		return "", fmt.Errorf("%v", pkg.Errors)