diff --git a/pkg/git/gogit/transport.go b/pkg/git/gogit/transport.go
index d30a2abd6..0ab3fbd67 100644
--- a/pkg/git/gogit/transport.go
+++ b/pkg/git/gogit/transport.go
@@ -17,6 +17,8 @@ limitations under the License.
 package gogit
 
 import (
+	"fmt"
+
 	"github.com/go-git/go-git/v5/plumbing/transport"
 	"github.com/go-git/go-git/v5/plumbing/transport/http"
 	"github.com/go-git/go-git/v5/plumbing/transport/ssh"
@@ -53,6 +55,10 @@ func transportAuth(opts *git.AuthOptions) (transport.AuthMethod, error) {
 			}
 			return pk, nil
 		}
+	case "":
+		return nil, fmt.Errorf("no transport type set")
+	default:
+		return nil, fmt.Errorf("unknown transport '%s'", opts.Transport)
 	}
 	return nil, nil
 }
diff --git a/pkg/git/gogit/transport_test.go b/pkg/git/gogit/transport_test.go
index f1863f0e8..93ea279d9 100644
--- a/pkg/git/gogit/transport_test.go
+++ b/pkg/git/gogit/transport_test.go
@@ -168,12 +168,16 @@ func Test_transportAuth(t *testing.T) {
 			wantErr: errors.New("knownhosts: knownhosts: missing host pattern"),
 		},
 		{
-			name: "Empty",
-			opts: &git.AuthOptions{},
-			wantFunc: func(g *WithT, t transport.AuthMethod, opts *git.AuthOptions) {
-				g.Expect(t).To(BeNil())
+			name:    "Empty",
+			opts:    &git.AuthOptions{},
+			wantErr: errors.New("no transport type set"),
+		},
+		{
+			name: "Unknown transport",
+			opts: &git.AuthOptions{
+				Transport: "foo",
 			},
-			wantErr: nil,
+			wantErr: errors.New("unknown transport 'foo'"),
 		},
 	}
 	for _, tt := range tests {