2 files changed, 45 insertions, 2 deletions
diff --git a/internal/executor/claude.go b/internal/executor/claude.go
index db4d0fa..4839a90 100644
--- a/internal/executor/claude.go
+++ b/internal/executor/claude.go
@@ -85,9 +85,16 @@ func (r *ClaudeRunner) Run(ctx context.Context, t *task.Task, e *storage.Executi
 	}
 
 	// Pre-assign session ID so we can resume after a BLOCKED state.
-	// If this is a resume execution the session ID is already set.
+	// For resume executions, the claude session continues under the original
+	// session ID (the one passed to --resume). Using the new exec's own UUID
+	// would cause a second block-and-resume cycle to pass the wrong --resume
+	// argument.
 	if e.SessionID == "" {
-		e.SessionID = e.ID // reuse execution UUID as session UUID (both are UUIDs)
+		if e.ResumeSessionID != "" {
+			e.SessionID = e.ResumeSessionID
+		} else {
+			e.SessionID = e.ID // reuse execution UUID as session UUID (both are UUIDs)
+		}
 	}
 
 	// For new (non-resume) executions with a project_dir, clone into a sandbox.
diff --git a/internal/executor/claude_test.go b/internal/executor/claude_test.go
index 1f95b4a..79f294e 100644
--- a/internal/executor/claude_test.go
+++ b/internal/executor/claude_test.go
@@ -227,6 +227,42 @@ func TestClaudeRunner_BuildArgs_PreambleBashNotDuplicated(t *testing.T) {
 	}
 }
 
+// TestClaudeRunner_Run_ResumeSetsSessionIDFromResumeSession verifies that when a
+// resume execution is itself blocked again, the stored SessionID is the original
+// resumed session, not the new execution's own UUID. Without this, a second
+// block-and-resume cycle passes the wrong --resume session ID and fails.
+func TestClaudeRunner_Run_ResumeSetsSessionIDFromResumeSession(t *testing.T) {
+	logDir := t.TempDir()
+	r := &ClaudeRunner{
+		BinaryPath: "true", // exits 0, no output
+		Logger:     slog.New(slog.NewTextHandler(io.Discard, nil)),
+		LogDir:     logDir,
+	}
+	tk := &task.Task{
+		Agent: task.AgentConfig{
+			Type:         "claude",
+			Instructions: "continue",
+			SkipPlanning: true,
+		},
+	}
+	exec := &storage.Execution{
+		ID:              "resume-exec-uuid",
+		TaskID:          "task-1",
+		ResumeSessionID: "original-session-uuid",
+		ResumeAnswer:    "yes",
+	}
+
+	// Run completes successfully (binary is "true").
+	_ = r.Run(context.Background(), tk, exec)
+
+	// SessionID must be the original session (ResumeSessionID), not the new
+	// exec's own ID. If it were exec.ID, a second blocked-then-resumed cycle
+	// would use the wrong --resume argument and fail.
+	if exec.SessionID != "original-session-uuid" {
+		t.Errorf("SessionID after resume Run: want %q, got %q", "original-session-uuid", exec.SessionID)
+	}
+}
+
 func TestClaudeRunner_Run_InaccessibleWorkingDir_ReturnsError(t *testing.T) {
 	r := &ClaudeRunner{
 		BinaryPath: "true", // would succeed if it ran