diff --git a/service/syncer/syncer.go b/service/syncer/syncer.go
index 9b25afe4..83308c5c 100644
--- a/service/syncer/syncer.go
+++ b/service/syncer/syncer.go
@@ -16,6 +16,7 @@ package syncer
 
 import (
 	"context"
+	"strings"
 	"time"
 
 	"github.com/drone/drone/core"
@@ -102,7 +103,14 @@ func (s *Synchronizer) Sync(ctx context.Context, user *core.User) (*core.Batch,
 			return nil, err
 		}
 		for _, repo := range repos {
-			if s.match(repo) {
+			if strings.Count(repo.Slug, "/") > 1 {
+				if logrus.GetLevel() == logrus.TraceLevel {
+					logger.WithField("namespace", repo.Namespace).
+						WithField("name", repo.Name).
+						WithField("uid", repo.UID).
+						Traceln("syncer: skipping subrepositories")
+				}
+			} else if s.match(repo) {
 				remote[repo.UID] = repo
 				if logrus.GetLevel() == logrus.TraceLevel {
 					logger.WithField("namespace", repo.Namespace).
diff --git a/service/syncer/syncer_test.go b/service/syncer/syncer_test.go
index 968ba875..4b8640e6 100644
--- a/service/syncer/syncer_test.go
+++ b/service/syncer/syncer_test.go
@@ -259,7 +259,7 @@ func TestSync_Revoke(t *testing.T) {
 // this test verifies that we invoke the batch update even
 // if there are no batch updates to make. This is important
 // because the batcher resets permissions and forces Drone
-// to re-synchrnoize.
+// to re-synchronize.
 func TestSync_EmptyBatch(t *testing.T) {
 	controller := gomock.NewController(t)
 	defer controller.Finish()
@@ -387,3 +387,50 @@ func TestSync_BatchError(t *testing.T) {
 		t.Errorf("Want error %s, got %s", want, got)
 	}
 }
+
+// this test verifies that sub-repositories are skipped. They
+// are unsupported by Drone and should not be ignored.
+func TestSync_SkipSubrepo(t *testing.T) {
+	controller := gomock.NewController(t)
+	defer controller.Finish()
+
+	user := &core.User{ID: 1}
+
+	userStore := mock.NewMockUserStore(controller)
+	userStore.EXPECT().Update(gomock.Any(), user).Return(nil)
+	userStore.EXPECT().Update(gomock.Any(), user).Return(nil)
+
+	batcher := mock.NewMockBatcher(controller)
+	batcher.EXPECT().Batch(gomock.Any(), gomock.Any(), gomock.Any()).Return(nil)
+
+	repoStore := mock.NewMockRepositoryStore(controller)
+	repoStore.EXPECT().List(gomock.Any(), gomock.Any()).Return([]*core.Repository{}, nil)
+
+	repoService := mock.NewMockRepositoryService(controller)
+	repoService.EXPECT().List(gomock.Any(), user).Return([]*core.Repository{
+		{
+			UID:        "1",
+			Slug:       "octocat/hello/world",
+			Namespace:  "octocat",
+			Name:       "hello-world",
+			Private:    false,
+			Visibility: core.VisibilityPublic,
+		},
+	}, nil)
+
+	s := New(
+		repoService,
+		repoStore,
+		userStore,
+		batcher,
+	)
+	got, err := s.Sync(context.Background(), user)
+	if err != nil {
+		t.Error(err)
+	}
+
+	want := &core.Batch{}
+	if diff := cmp.Diff(got, want); len(diff) != 0 {
+		t.Errorf(diff)
+	}
+}