diff --git a/repository/git.go b/repository/git.go
index 55dacfbb..5aa353c6 100644
--- a/repository/git.go
+++ b/repository/git.go
@@ -67,6 +67,30 @@ func RunInteractiveGitCommand(ctx context.Context, dir string, w io.Writer, args
 	return cmd.Run()
 }
 
+func isShallowRepository(ctx context.Context, repo string) (bool, error) {
+	isShallow, err := RunGitCommand(ctx, repo, "rev-parse", "--is-shallow-repository")
+	if err != nil {
+		return false, err
+	}
+
+	return strings.TrimSpace(isShallow) == "true", nil
+}
+
+func ensureRepositoryNotShallow(ctx context.Context, repo string) error {
+	isShallow, err := isShallowRepository(ctx, repo)
+	if err != nil {
+		return err
+	}
+
+	if !isShallow {
+		return nil
+	}
+
+	slog.Info("Repository is shallow, fetching full history", "repository", repo)
+	_, err = RunGitCommand(ctx, repo, "fetch", "--unshallow")
+	return err
+}
+
 func getContainerUseRemote(ctx context.Context, repo string) (string, error) {
 	// Check if we already have a container-use remote
 	cuRemote, err := RunGitCommand(ctx, repo, "remote", "get-url", "container-use")
@@ -139,6 +163,10 @@ func (r *Repository) initializeWorktree(ctx context.Context, id, gitRef string)
 		}
 		resolvedRef = strings.TrimSpace(resolvedRef)
 
+		if err := ensureRepositoryNotShallow(ctx, r.userRepoPath); err != nil {
+			return err
+		}
+
 		_, err = RunGitCommand(ctx, r.userRepoPath, "push", containerUseRemote, fmt.Sprintf("%s:refs/heads/%s", resolvedRef, id))
 		if err != nil {
 			// Retry once on failure
diff --git a/repository/repository_test.go b/repository/repository_test.go
index 2d2924b4..8fd2dbb0 100644
--- a/repository/repository_test.go
+++ b/repository/repository_test.go
@@ -66,3 +66,55 @@ func TestRepositoryOpen(t *testing.T) {
 		assert.Equal(t, repo.forkRepoPath, strings.TrimSpace(remote))
 	})
 }
+
+func TestInitializeWorktreeUnshallowOnShallowClone(t *testing.T) {
+	ctx := context.Background()
+	tempDir := t.TempDir()
+
+	originRepo := filepath.Join(tempDir, "origin")
+	shallowRepo := filepath.Join(tempDir, "shallow")
+	bareRemote := filepath.Join(tempDir, "remote.git")
+	base := filepath.Join(tempDir, "base")
+
+	err := os.MkdirAll(originRepo, 0755)
+	require.NoError(t, err)
+	_, err = RunGitCommand(ctx, originRepo, "init")
+	require.NoError(t, err)
+	_, err = RunGitCommand(ctx, originRepo, "config", "user.email", "test@example.com")
+	require.NoError(t, err)
+	_, err = RunGitCommand(ctx, originRepo, "config", "user.name", "Test User")
+	require.NoError(t, err)
+
+	err = os.WriteFile(filepath.Join(originRepo, "README.md"), []byte("initial"), 0644)
+	require.NoError(t, err)
+	_, err = RunGitCommand(ctx, originRepo, "add", "README.md")
+	require.NoError(t, err)
+	_, err = RunGitCommand(ctx, originRepo, "commit", "-m", "initial")
+	require.NoError(t, err)
+	err = os.WriteFile(filepath.Join(originRepo, "README.md"), []byte("updated"), 0644)
+	require.NoError(t, err)
+	_, err = RunGitCommand(ctx, originRepo, "commit", "-am", "update")
+	require.NoError(t, err)
+
+	_, err = RunGitCommand(ctx, tempDir, "clone", "--bare", originRepo, bareRemote)
+	require.NoError(t, err)
+	_, err = RunGitCommand(ctx, tempDir, "clone", "--depth=1", "file://"+bareRemote, shallowRepo)
+	require.NoError(t, err)
+	isShallow, err := isShallowRepository(ctx, shallowRepo)
+	require.NoError(t, err)
+	require.True(t, isShallow, "test setup should create a shallow repository")
+
+	repo, err := OpenWithBasePath(ctx, shallowRepo, base)
+	require.NoError(t, err)
+	defer repo.deleteWorktree("issue-248-shallow")
+
+	_, _, err = repo.initializeWorktree(ctx, "issue-248-shallow", "HEAD")
+	require.NoError(t, err)
+
+	isShallow, err = isShallowRepository(ctx, shallowRepo)
+	require.NoError(t, err)
+	assert.False(t, isShallow, "shallow repository should be unshallowed during environment creation")
+
+	_, err = RunGitCommand(ctx, repo.forkRepoPath, "rev-parse", "--verify", "issue-248-shallow")
+	require.NoError(t, err)
+}