diff --git a/src/renderer/src/lib/workspace-browser-tab-open.test.ts b/src/renderer/src/lib/workspace-browser-tab-open.test.ts
index d414316b52f..765f452f8f7 100644
--- a/src/renderer/src/lib/workspace-browser-tab-open.test.ts
+++ b/src/renderer/src/lib/workspace-browser-tab-open.test.ts
@@ -4,6 +4,7 @@ import {
   toRuntimeExecutionHostId,
   toSshExecutionHostId
 } from '../../../shared/execution-host'
+import { BROWSER_SCREENCAST_RUNTIME_CAPABILITY } from '../../../shared/protocol-version'
 import {
   canOpenWorkspaceBrowserTabOnRuntime,
   openWorkspaceBrowserTab
@@ -43,7 +44,10 @@ function ownerState(hostId?: string, runtimeOwnerEnvironmentId?: string): Record
 function browserCapableRuntime(environmentId: string): Record<string, unknown> {
   return {
     runtimeStatusByEnvironmentId: new Map([
-      [environmentId, { status: { capabilities: ['browser.screencast.v1'] }, checkedAt: 1 }]
+      [
+        environmentId,
+        { status: { capabilities: [BROWSER_SCREENCAST_RUNTIME_CAPABILITY] }, checkedAt: 1 }
+      ]
     ])
   }
 }
@@ -164,6 +168,27 @@ describe('openWorkspaceBrowserTab', () => {
     expect(mocks.state.createBrowserTab).not.toHaveBeenCalled()
   })
 
+  it('does not fall back to a client browser when asserted runtime creation fails', async () => {
+    mocks.state = {
+      ...ownerState(toRuntimeExecutionHostId('hub-a')),
+      ...browserCapableRuntime('hub-a'),
+      createBrowserTab: vi.fn(),
+      defaultBrowserSessionProfileId: 'client-profile',
+      defaultBrowserSessionProfileIdByHostId: {}
+    }
+    mocks.createRemote.mockResolvedValue(false)
+
+    await expect(
+      openWorkspaceBrowserTab({
+        workspaceId: WORKSPACE_ID,
+        url: 'https://example.com/',
+        intent: { kind: 'url' },
+        expectedRuntimeEnvironmentId: 'hub-a'
+      })
+    ).rejects.toThrow('Unable to open URL.')
+    expect(mocks.state.createBrowserTab).not.toHaveBeenCalled()
+  })
+
   // Two dev servers on one host must not share a tab title.
   it('keeps the port in local-dev tab titles', async () => {
     const createBrowserTab = vi.fn()
diff --git a/src/renderer/src/lib/workspace-browser-tab-open.ts b/src/renderer/src/lib/workspace-browser-tab-open.ts
index 0ef67b1cfce..144b9cd60f6 100644
--- a/src/renderer/src/lib/workspace-browser-tab-open.ts
+++ b/src/renderer/src/lib/workspace-browser-tab-open.ts
@@ -8,6 +8,7 @@ import {
   type ExecutionHostId
 } from '../../../shared/execution-host'
 import { SEARCH_ENGINE_LABELS, type SearchEngine } from '../../../shared/browser-url'
+import { BROWSER_SCREENCAST_RUNTIME_CAPABILITY } from '../../../shared/protocol-version'
 import {
   getClientCreationActionPolicy,
   type ClientCreationActionAvailability
@@ -25,15 +26,21 @@ export type OpenWorkspaceBrowserTabRequest = {
 }
 
 function isExpectedRuntimeBrowserRoute(
-  availability: ClientCreationActionAvailability,
+  state: AppState,
   route: ReturnType<typeof resolveWorktreeOperationRoute>,
   expectedRuntimeEnvironmentId: string
 ): boolean {
-  if (availability.state !== 'enabled' || availability.provider !== 'paired-runtime' || !route) {
+  if (!route) {
     return false
   }
+  const expectedEnvironmentId = expectedRuntimeEnvironmentId.trim()
   const environmentId = route.runtimeEnvironmentId?.trim() || null
-  if (environmentId !== expectedRuntimeEnvironmentId.trim()) {
+  const capabilities =
+    state.runtimeStatusByEnvironmentId?.get(expectedEnvironmentId)?.status?.capabilities
+  if (
+    environmentId !== expectedEnvironmentId ||
+    !capabilities?.includes(BROWSER_SCREENCAST_RUNTIME_CAPABILITY)
+  ) {
     return false
   }
   const host = parseExecutionHostId(route.executionHostId)
@@ -48,9 +55,8 @@ export function canOpenWorkspaceBrowserTabOnRuntime(
   workspaceId: string,
   expectedRuntimeEnvironmentId: string
 ): boolean {
-  const availability = getClientCreationActionPolicy(state, workspaceId)['managed-browser']
   const route = resolveWorktreeOperationRoute(state, workspaceId)
-  return isExpectedRuntimeBrowserRoute(availability, route, expectedRuntimeEnvironmentId)
+  return isExpectedRuntimeBrowserRoute(state, route, expectedRuntimeEnvironmentId)
 }
 
 // Why: concurrent URL tabs are indistinguishable under a shared "Open URL"
@@ -166,7 +172,7 @@ export async function openWorkspaceBrowserTab(
   const expectedEnvironmentId = request.expectedRuntimeEnvironmentId?.trim() || null
   if (
     expectedEnvironmentId &&
-    !isExpectedRuntimeBrowserRoute(availability, route, expectedEnvironmentId)
+    !isExpectedRuntimeBrowserRoute(state, route, expectedEnvironmentId)
   ) {
     throw openFailure(presentation.error, 'asserted runtime cannot provide this managed browser')
   }