diff --git a/pentestagent/interface/tui.py b/pentestagent/interface/tui.py
index df4b970..370f81c 100644
--- a/pentestagent/interface/tui.py
+++ b/pentestagent/interface/tui.py
@@ -2156,6 +2156,35 @@ Be concise. Use the actual data from notes."""
                     try:
                         if marker.exists():
                             marker.unlink()
+                        # Clear TUI and agent target when workspace is deactivated
+                        self.target = ""
+                        try:
+                            self._apply_target_display("")
+                        except Exception:
+                            pass
+                        if self.agent:
+                            try:
+                                # Clear agent's target and any manual override
+                                self.agent.target = ""
+                                try:
+                                    if hasattr(self.agent, "_manual_target"):
+                                        delattr(self.agent, "_manual_target")
+                                except Exception:
+                                    pass
+                                from pentestagent.agents.base_agent import AgentMessage
+
+                                self.agent.conversation_history.append(
+                                    AgentMessage(
+                                        role="system",
+                                        content=(
+                                            f"Workspace '{active}' deactivated; cleared target"
+                                        ),
+                                    )
+                                )
+                            except Exception:
+                                logging.getLogger(__name__).exception(
+                                    "Failed to clear agent target on workspace clear"
+                                )
                         self._add_system(f"Workspace '{active}' deactivated.")
                     except Exception as e:
                         self._add_system(f"Error deactivating workspace: {e}")