diff --git a/cmd/resume.go b/cmd/resume.go
index 53d9957..c1943b3 100644
--- a/cmd/resume.go
+++ b/cmd/resume.go
@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -38,8 +39,21 @@ func init() {
 	rootCmd.AddCommand(resumeCmd)
 }
 
+// errArchivedWorkspace is the sentinel doResume returns when the user
+// asks to resume an archived workspace. doResume already prints the
+// full [ctask] diagnostic + restore hint to stderr, so the cmd-layer
+// wrapper flips SilenceErrors to suppress Cobra's redundant trailing
+// "Error: workspace archived" line. All other errors (lookup failure,
+// metadata write failure, etc.) flow through Cobra's default
+// rendering unchanged.
+var errArchivedWorkspace = errors.New("workspace archived")
+
 func runResume(cmd *cobra.Command, args []string) error {
-	return doResume(args[0], resumeContainer, resumeShell, resumeForce, resumeAgent, resumeDirect)
+	err := doResume(args[0], resumeContainer, resumeShell, resumeForce, resumeAgent, resumeDirect)
+	if errors.Is(err, errArchivedWorkspace) {
+		cmd.SilenceErrors = true
+	}
+	return err
 }
 
 // doResume is the shared resume logic used by both `resume` and `last`.
@@ -59,7 +73,7 @@ func doResume(query string, container, useShell, force bool, agentOverride strin
 
 	if ws.Meta.Status == "archived" {
 		fmt.Fprint(os.Stderr, formatResumeRestoreHint(query))
-		return fmt.Errorf("workspace archived")
+		return errArchivedWorkspace
 	}
 
 	// updated_at bump (existing v0.4 behavior).
diff --git a/cmd/resume_archived_polish_test.go b/cmd/resume_archived_polish_test.go
new file mode 100644
index 0000000..253bfb3
--- /dev/null
+++ b/cmd/resume_archived_polish_test.go
@@ -0,0 +1,117 @@
+package cmd
+
+import (
+	"bytes"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/spf13/cobra"
+	"github.com/warrenronsiek/ctask/internal/workspace"
+)
+
+// TestResumeArchivedHintNoDuplicateError exercises resume through Cobra
+// (not just runResume directly) so the SilenceErrors path is observed
+// end-to-end. After v0.5.4 the [ctask] diagnostic block must print on
+// its own — Cobra's default trailing "Error: workspace archived" line
+// is suppressed via the conditional SilenceErrors set inside runResume.
+//
+// This guards against:
+//   - Reverting to a generic fmt.Errorf("workspace archived") that no
+//     longer matches the sentinel.
+//   - Removing the SilenceErrors flip.
+//   - A future runResume refactor that returns the error before the
+//     conditional check runs.
+func TestResumeArchivedHintNoDuplicateError(t *testing.T) {
+	withInvocationName(t, "ctask")
+
+	root := t.TempDir()
+	wsDir := filepath.Join(root, "general", "2026-04-22_archived-poll")
+	if err := os.MkdirAll(wsDir, 0755); err != nil {
+		t.Fatalf("MkdirAll: %v", err)
+	}
+	now := time.Now().UTC().Truncate(time.Second)
+	archived := now.Add(-time.Hour)
+	meta := &workspace.TaskMeta{
+		ID: "t", Slug: "archived-poll", Title: "archived-poll",
+		CreatedAt: now, UpdatedAt: archived,
+		ArchivedAt: &archived,
+		Status:     "archived",
+		Category:   "general",
+		Type:       "task",
+		Mode:       "local",
+		Agent:      "claude",
+	}
+	if err := workspace.WriteMeta(filepath.Join(wsDir, "task.yaml"), meta); err != nil {
+		t.Fatalf("WriteMeta: %v", err)
+	}
+
+	prevRoot := os.Getenv("CTASK_ROOT")
+	os.Setenv("CTASK_ROOT", root)
+	t.Cleanup(func() {
+		if prevRoot == "" {
+			os.Unsetenv("CTASK_ROOT")
+		} else {
+			os.Setenv("CTASK_ROOT", prevRoot)
+		}
+	})
+
+	// resumeCmd is a package global; restore SilenceErrors after the test
+	// so other tests against the same command see the original setting.
+	prevSilence := resumeCmd.SilenceErrors
+	t.Cleanup(func() { resumeCmd.SilenceErrors = prevSilence })
+
+	// Drive a fresh Cobra parent so we don't invoke unrelated commands
+	// during the test. AddCommand removes from the previous parent first.
+	parent := &cobra.Command{Use: "ctask-test"}
+	parent.AddCommand(resumeCmd)
+	t.Cleanup(func() { rootCmd.AddCommand(resumeCmd) })
+
+	parent.SetArgs([]string{"resume", "archived-poll"})
+
+	// Cobra writes the trailing "Error: ..." line to its configured
+	// error output, NOT to os.Stderr by default. Capture both: the
+	// [ctask] diagnostic goes to os.Stderr (via fmt.Fprint), while the
+	// would-be Cobra trailing line would go to parent's err output.
+	var cobraErrBuf bytes.Buffer
+	parent.SetErr(&cobraErrBuf)
+	parent.SetOut(&bytes.Buffer{})
+
+	stderrR, stderrW, _ := os.Pipe()
+	prevStderr := os.Stderr
+	os.Stderr = stderrW
+	defer func() { os.Stderr = prevStderr }()
+
+	execErr := parent.Execute()
+
+	stderrW.Close()
+	var directStderr bytes.Buffer
+	directStderr.ReadFrom(stderrR)
+
+	if execErr == nil {
+		t.Fatal("expected error from resuming archived workspace")
+	}
+	if !errors.Is(execErr, errArchivedWorkspace) {
+		t.Errorf("Execute should return errArchivedWorkspace, got %v", execErr)
+	}
+
+	// The [ctask] diagnostic must be present (printed to os.Stderr by
+	// runResume's stderr write).
+	gotStderr := directStderr.String()
+	if !strings.Contains(gotStderr, "[ctask] error: workspace") {
+		t.Errorf("[ctask] diagnostic missing from stderr:\n%s", gotStderr)
+	}
+	if !strings.Contains(gotStderr, "ctask restore archived-poll") {
+		t.Errorf("restore hint missing from stderr:\n%s", gotStderr)
+	}
+
+	// The Cobra-default "Error: workspace archived" line must NOT appear.
+	// It would normally land on parent's error writer.
+	cobraOut := cobraErrBuf.String()
+	if strings.Contains(cobraOut, "Error:") {
+		t.Errorf("Cobra default Error: line was not suppressed:\n%s", cobraOut)
+	}
+}