diff --git a/plugin/plugin.go b/plugin/plugin.go
index 109f611..a67be44 100644
--- a/plugin/plugin.go
+++ b/plugin/plugin.go
@@ -34,7 +34,7 @@ type Args struct {
 
 // Exec executes the plugin.
 func Exec(ctx context.Context, args Args) error {
-	if err := VerifyArgs(&args); err != nil {
+	if err := verifyArgs(&args); err != nil {
 		return err
 	}
 
@@ -60,7 +60,7 @@ func Exec(ctx context.Context, args Args) error {
 	return nil
 }
 
-func VerifyArgs(args *Args) error {
+func verifyArgs(args *Args) error {
 	if args.RegistryUrl == "" {
 		return fmt.Errorf("registry url is required")
 	}
diff --git a/plugin/plugin_test.go b/plugin/plugin_test.go
index 54b840b..11114ba 100644
--- a/plugin/plugin_test.go
+++ b/plugin/plugin_test.go
@@ -14,7 +14,7 @@ import (
 func TestVerifyArgs(t *testing.T) {
 	var err error
 
-	err = VerifyArgs(&Args{
+	err = verifyArgs(&Args{
 		RegistryUrl: "https://registry.hub.docker.com",
 	})
 
@@ -22,7 +22,7 @@ func TestVerifyArgs(t *testing.T) {
 		t.Error(err)
 	}
 
-	err = VerifyArgs(&Args{
+	err = verifyArgs(&Args{
 		Username: "octocat",
 		Password: "pass",
 	})
@@ -31,7 +31,7 @@ func TestVerifyArgs(t *testing.T) {
 		t.Error(err)
 	}
 
-	err = VerifyArgs(&Args{
+	err = verifyArgs(&Args{
 		RegistryUrl: "https://registry.hub.docker.com",
 		Username:    "octocat",
 		Password:    "pass",
@@ -41,7 +41,7 @@ func TestVerifyArgs(t *testing.T) {
 		t.Error(err)
 	}
 
-	err = VerifyArgs(&Args{
+	err = verifyArgs(&Args{
 		RegistryUrl: "https://registry.hub.docker.com",
 		Username:    "octocat",
 		Password:    "pass",