diff --git a/crates/workspace/src/multi_workspace.rs b/crates/workspace/src/multi_workspace.rs
index 862f7c7b267721833fa395e501b604d30745a1b7..10a5ce70ead2d5aea7cc21a9af53ee9f216859c3 100644
--- a/crates/workspace/src/multi_workspace.rs
+++ b/crates/workspace/src/multi_workspace.rs
@@ -1113,178 +1113,3 @@ impl Render for MultiWorkspace {
         )
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use fs::FakeFs;
-    use gpui::TestAppContext;
-    use settings::SettingsStore;
-
-    fn init_test(cx: &mut TestAppContext) {
-        cx.update(|cx| {
-            let settings_store = SettingsStore::test(cx);
-            cx.set_global(settings_store);
-            theme_settings::init(theme::LoadThemes::JustBase, cx);
-            DisableAiSettings::register(cx);
-            cx.update_flags(false, vec!["agent-v2".into()]);
-        });
-    }
-
-    #[gpui::test]
-    async fn test_sidebar_disabled_when_disable_ai_is_enabled(cx: &mut TestAppContext) {
-        init_test(cx);
-        let fs = FakeFs::new(cx.executor());
-        let project = Project::test(fs, [], cx).await;
-
-        let (multi_workspace, cx) =
-            cx.add_window_view(|window, cx| MultiWorkspace::test_new(project, window, cx));
-
-        multi_workspace.read_with(cx, |mw, cx| {
-            assert!(mw.multi_workspace_enabled(cx));
-        });
-
-        multi_workspace.update_in(cx, |mw, _window, cx| {
-            mw.open_sidebar(cx);
-            assert!(mw.sidebar_open());
-        });
-
-        cx.update(|_window, cx| {
-            DisableAiSettings::override_global(DisableAiSettings { disable_ai: true }, cx);
-        });
-        cx.run_until_parked();
-
-        multi_workspace.read_with(cx, |mw, cx| {
-            assert!(
-                !mw.sidebar_open(),
-                "Sidebar should be closed when disable_ai is true"
-            );
-            assert!(
-                !mw.multi_workspace_enabled(cx),
-                "Multi-workspace should be disabled when disable_ai is true"
-            );
-        });
-
-        multi_workspace.update_in(cx, |mw, window, cx| {
-            mw.toggle_sidebar(window, cx);
-        });
-        multi_workspace.read_with(cx, |mw, _cx| {
-            assert!(
-                !mw.sidebar_open(),
-                "Sidebar should remain closed when toggled with disable_ai true"
-            );
-        });
-
-        cx.update(|_window, cx| {
-            DisableAiSettings::override_global(DisableAiSettings { disable_ai: false }, cx);
-        });
-        cx.run_until_parked();
-
-        multi_workspace.read_with(cx, |mw, cx| {
-            assert!(
-                mw.multi_workspace_enabled(cx),
-                "Multi-workspace should be enabled after re-enabling AI"
-            );
-            assert!(
-                !mw.sidebar_open(),
-                "Sidebar should still be closed after re-enabling AI (not auto-opened)"
-            );
-        });
-
-        multi_workspace.update_in(cx, |mw, window, cx| {
-            mw.toggle_sidebar(window, cx);
-        });
-        multi_workspace.read_with(cx, |mw, _cx| {
-            assert!(
-                mw.sidebar_open(),
-                "Sidebar should open when toggled after re-enabling AI"
-            );
-        });
-    }
-
-    #[gpui::test]
-    async fn test_replace(cx: &mut TestAppContext) {
-        init_test(cx);
-        let fs = FakeFs::new(cx.executor());
-        let project_a = Project::test(fs.clone(), [], cx).await;
-        let project_b = Project::test(fs.clone(), [], cx).await;
-        let project_c = Project::test(fs.clone(), [], cx).await;
-        let project_d = Project::test(fs.clone(), [], cx).await;
-
-        let (multi_workspace, cx) = cx
-            .add_window_view(|window, cx| MultiWorkspace::test_new(project_a.clone(), window, cx));
-
-        let workspace_a_id =
-            multi_workspace.read_with(cx, |mw, _cx| mw.workspaces()[0].entity_id());
-
-        // Replace the only workspace (single-workspace case).
-        let workspace_b = multi_workspace.update_in(cx, |mw, window, cx| {
-            let workspace = cx.new(|cx| Workspace::test_new(project_b.clone(), window, cx));
-            mw.replace(workspace.clone(), &*window, cx);
-            workspace
-        });
-
-        multi_workspace.read_with(cx, |mw, _cx| {
-            assert_eq!(mw.workspaces().len(), 1);
-            assert_eq!(
-                mw.workspaces()[0].entity_id(),
-                workspace_b.entity_id(),
-                "slot should now be project_b"
-            );
-            assert_ne!(
-                mw.workspaces()[0].entity_id(),
-                workspace_a_id,
-                "project_a should be gone"
-            );
-        });
-
-        // Add project_c as a second workspace, then replace it with project_d.
-        let workspace_c = multi_workspace.update_in(cx, |mw, window, cx| {
-            mw.test_add_workspace(project_c.clone(), window, cx)
-        });
-
-        multi_workspace.read_with(cx, |mw, _cx| {
-            assert_eq!(mw.workspaces().len(), 2);
-            assert_eq!(mw.active_workspace_index(), 1);
-        });
-
-        let workspace_d = multi_workspace.update_in(cx, |mw, window, cx| {
-            let workspace = cx.new(|cx| Workspace::test_new(project_d.clone(), window, cx));
-            mw.replace(workspace.clone(), &*window, cx);
-            workspace
-        });
-
-        multi_workspace.read_with(cx, |mw, _cx| {
-            assert_eq!(mw.workspaces().len(), 2, "should still have 2 workspaces");
-            assert_eq!(mw.active_workspace_index(), 1);
-            assert_eq!(
-                mw.workspaces()[1].entity_id(),
-                workspace_d.entity_id(),
-                "active slot should now be project_d"
-            );
-            assert_ne!(
-                mw.workspaces()[1].entity_id(),
-                workspace_c.entity_id(),
-                "project_c should be gone"
-            );
-        });
-
-        // Replace with workspace_b which is already in the list — should just switch.
-        multi_workspace.update_in(cx, |mw, window, cx| {
-            mw.replace(workspace_b.clone(), &*window, cx);
-        });
-
-        multi_workspace.read_with(cx, |mw, _cx| {
-            assert_eq!(
-                mw.workspaces().len(),
-                2,
-                "no workspace should be added or removed"
-            );
-            assert_eq!(
-                mw.active_workspace_index(),
-                0,
-                "should have switched to workspace_b"
-            );
-        });
-    }
-}
diff --git a/crates/workspace/src/multi_workspace_tests.rs b/crates/workspace/src/multi_workspace_tests.rs
new file mode 100644
index 0000000000000000000000000000000000000000..50161121719ec7b2835fd11e389f24860e57d8f5
--- /dev/null
+++ b/crates/workspace/src/multi_workspace_tests.rs
@@ -0,0 +1,172 @@
+use super::*;
+use feature_flags::FeatureFlagAppExt;
+use fs::FakeFs;
+use gpui::TestAppContext;
+use project::DisableAiSettings;
+use settings::SettingsStore;
+
+fn init_test(cx: &mut TestAppContext) {
+    cx.update(|cx| {
+        let settings_store = SettingsStore::test(cx);
+        cx.set_global(settings_store);
+        theme_settings::init(theme::LoadThemes::JustBase, cx);
+        DisableAiSettings::register(cx);
+        cx.update_flags(false, vec!["agent-v2".into()]);
+    });
+}
+
+#[gpui::test]
+async fn test_sidebar_disabled_when_disable_ai_is_enabled(cx: &mut TestAppContext) {
+    init_test(cx);
+    let fs = FakeFs::new(cx.executor());
+    let project = Project::test(fs, [], cx).await;
+
+    let (multi_workspace, cx) =
+        cx.add_window_view(|window, cx| MultiWorkspace::test_new(project, window, cx));
+
+    multi_workspace.read_with(cx, |mw, cx| {
+        assert!(mw.multi_workspace_enabled(cx));
+    });
+
+    multi_workspace.update_in(cx, |mw, _window, cx| {
+        mw.open_sidebar(cx);
+        assert!(mw.sidebar_open());
+    });
+
+    cx.update(|_window, cx| {
+        DisableAiSettings::override_global(DisableAiSettings { disable_ai: true }, cx);
+    });
+    cx.run_until_parked();
+
+    multi_workspace.read_with(cx, |mw, cx| {
+        assert!(
+            !mw.sidebar_open(),
+            "Sidebar should be closed when disable_ai is true"
+        );
+        assert!(
+            !mw.multi_workspace_enabled(cx),
+            "Multi-workspace should be disabled when disable_ai is true"
+        );
+    });
+
+    multi_workspace.update_in(cx, |mw, window, cx| {
+        mw.toggle_sidebar(window, cx);
+    });
+    multi_workspace.read_with(cx, |mw, _cx| {
+        assert!(
+            !mw.sidebar_open(),
+            "Sidebar should remain closed when toggled with disable_ai true"
+        );
+    });
+
+    cx.update(|_window, cx| {
+        DisableAiSettings::override_global(DisableAiSettings { disable_ai: false }, cx);
+    });
+    cx.run_until_parked();
+
+    multi_workspace.read_with(cx, |mw, cx| {
+        assert!(
+            mw.multi_workspace_enabled(cx),
+            "Multi-workspace should be enabled after re-enabling AI"
+        );
+        assert!(
+            !mw.sidebar_open(),
+            "Sidebar should still be closed after re-enabling AI (not auto-opened)"
+        );
+    });
+
+    multi_workspace.update_in(cx, |mw, window, cx| {
+        mw.toggle_sidebar(window, cx);
+    });
+    multi_workspace.read_with(cx, |mw, _cx| {
+        assert!(
+            mw.sidebar_open(),
+            "Sidebar should open when toggled after re-enabling AI"
+        );
+    });
+}
+
+#[gpui::test]
+async fn test_replace(cx: &mut TestAppContext) {
+    init_test(cx);
+    let fs = FakeFs::new(cx.executor());
+    let project_a = Project::test(fs.clone(), [], cx).await;
+    let project_b = Project::test(fs.clone(), [], cx).await;
+    let project_c = Project::test(fs.clone(), [], cx).await;
+    let project_d = Project::test(fs.clone(), [], cx).await;
+
+    let (multi_workspace, cx) =
+        cx.add_window_view(|window, cx| MultiWorkspace::test_new(project_a.clone(), window, cx));
+
+    let workspace_a_id = multi_workspace.read_with(cx, |mw, _cx| mw.workspaces()[0].entity_id());
+
+    // Replace the only workspace (single-workspace case).
+    let workspace_b = multi_workspace.update_in(cx, |mw, window, cx| {
+        let workspace = cx.new(|cx| Workspace::test_new(project_b.clone(), window, cx));
+        mw.replace(workspace.clone(), &*window, cx);
+        workspace
+    });
+
+    multi_workspace.read_with(cx, |mw, _cx| {
+        assert_eq!(mw.workspaces().len(), 1);
+        assert_eq!(
+            mw.workspaces()[0].entity_id(),
+            workspace_b.entity_id(),
+            "slot should now be project_b"
+        );
+        assert_ne!(
+            mw.workspaces()[0].entity_id(),
+            workspace_a_id,
+            "project_a should be gone"
+        );
+    });
+
+    // Add project_c as a second workspace, then replace it with project_d.
+    let workspace_c = multi_workspace.update_in(cx, |mw, window, cx| {
+        mw.test_add_workspace(project_c.clone(), window, cx)
+    });
+
+    multi_workspace.read_with(cx, |mw, _cx| {
+        assert_eq!(mw.workspaces().len(), 2);
+        assert_eq!(mw.active_workspace_index(), 1);
+    });
+
+    let workspace_d = multi_workspace.update_in(cx, |mw, window, cx| {
+        let workspace = cx.new(|cx| Workspace::test_new(project_d.clone(), window, cx));
+        mw.replace(workspace.clone(), &*window, cx);
+        workspace
+    });
+
+    multi_workspace.read_with(cx, |mw, _cx| {
+        assert_eq!(mw.workspaces().len(), 2, "should still have 2 workspaces");
+        assert_eq!(mw.active_workspace_index(), 1);
+        assert_eq!(
+            mw.workspaces()[1].entity_id(),
+            workspace_d.entity_id(),
+            "active slot should now be project_d"
+        );
+        assert_ne!(
+            mw.workspaces()[1].entity_id(),
+            workspace_c.entity_id(),
+            "project_c should be gone"
+        );
+    });
+
+    // Replace with workspace_b which is already in the list — should just switch.
+    multi_workspace.update_in(cx, |mw, window, cx| {
+        mw.replace(workspace_b.clone(), &*window, cx);
+    });
+
+    multi_workspace.read_with(cx, |mw, _cx| {
+        assert_eq!(
+            mw.workspaces().len(),
+            2,
+            "no workspace should be added or removed"
+        );
+        assert_eq!(
+            mw.active_workspace_index(),
+            0,
+            "should have switched to workspace_b"
+        );
+    });
+}
diff --git a/crates/workspace/src/workspace.rs b/crates/workspace/src/workspace.rs
index 33d1befe38e3b48a39377547bd433398b37d6a77..ae05c2c59012b2caf217ac54a80b377aee87f09d 100644
--- a/crates/workspace/src/workspace.rs
+++ b/crates/workspace/src/workspace.rs
@@ -5,6 +5,8 @@ pub mod invalid_item_view;
 pub mod item;
 mod modal_layer;
 mod multi_workspace;
+#[cfg(test)]
+mod multi_workspace_tests;
 pub mod notifications;
 pub mod pane;
 pub mod pane_group;