diff --git a/Sources/TerminalController.swift b/Sources/TerminalController.swift
index 6227cbaf..2b3dd830 100644
--- a/Sources/TerminalController.swift
+++ b/Sources/TerminalController.swift
@@ -6283,6 +6283,7 @@ class TerminalController {
             return .err(code: "unavailable", message: "TabManager not available", data: nil)
         }
 
+        let explicitSurfaceId = v2UUID(params, "surface_id")
         let title = (params["title"] as? String) ?? "Notification"
         let subtitle = (params["subtitle"] as? String) ?? ""
         let body = (params["body"] as? String) ?? ""
@@ -6293,7 +6294,15 @@ class TerminalController {
                 result = .err(code: "not_found", message: "Workspace not found", data: nil)
                 return
             }
-            let surfaceId = ws.focusedPanelId
+            if let explicitSurfaceId, ws.panels[explicitSurfaceId] == nil {
+                result = .err(
+                    code: "not_found",
+                    message: "Surface not found",
+                    data: ["surface_id": explicitSurfaceId.uuidString]
+                )
+                return
+            }
+            let surfaceId = explicitSurfaceId ?? ws.focusedPanelId
             TerminalNotificationStore.shared.addNotification(
                 tabId: ws.id,
                 surfaceId: surfaceId,
diff --git a/cmuxTests/TerminalControllerSocketSecurityTests.swift b/cmuxTests/TerminalControllerSocketSecurityTests.swift
index 16224347..10ace119 100644
--- a/cmuxTests/TerminalControllerSocketSecurityTests.swift
+++ b/cmuxTests/TerminalControllerSocketSecurityTests.swift
@@ -150,9 +150,9 @@ final class TerminalControllerSocketSecurityTests: XCTestCase {
 
     func testNotificationCreateUsesExplicitSurfaceIDWhenProvided() async throws {
         let socketPath = makeSocketPath("notify-surface")
-        let manager = TabManager()
         let store = TerminalNotificationStore.shared
         let appDelegate = AppDelegate.shared ?? AppDelegate()
+        let manager = appDelegate.tabManager ?? TabManager()
 
         let originalTabManager = appDelegate.tabManager
         let originalNotificationStore = appDelegate.notificationStore
@@ -162,15 +162,18 @@ final class TerminalControllerSocketSecurityTests: XCTestCase {
         appDelegate.tabManager = manager
         appDelegate.notificationStore = store
 
+        let workspace = manager.addWorkspace(select: true)
         defer {
+            if manager.tabs.contains(where: { $0.id == workspace.id }) {
+                manager.closeWorkspace(workspace)
+            }
             store.replaceNotificationsForTesting([])
             store.resetNotificationDeliveryHandlerForTesting()
             appDelegate.tabManager = originalTabManager
             appDelegate.notificationStore = originalNotificationStore
         }
 
-        guard let workspace = manager.selectedWorkspace,
-              let focusedPanelId = workspace.focusedPanelId else {
+        guard let focusedPanelId = workspace.focusedPanelId else {
             XCTFail("Expected selected workspace with a focused panel")
             return
         }
@@ -206,7 +209,8 @@ final class TerminalControllerSocketSecurityTests: XCTestCase {
             }
         }
 
-        let result = try XCTUnwrap(response["result"] as? [String: Any])
+        XCTAssertEqual(response["ok"] as? Bool, true, "Unexpected JSON-RPC response: \(response)")
+        let result = try XCTUnwrap(response["result"] as? [String: Any], "Unexpected JSON-RPC response: \(response)")
         XCTAssertEqual(result["surface_id"] as? String, targetPanel.id.uuidString)
         XCTAssertTrue(store.hasUnreadNotification(forTabId: workspace.id, surfaceId: targetPanel.id))
         XCTAssertFalse(store.hasUnreadNotification(forTabId: workspace.id, surfaceId: focusedPanelId))