diff --git a/src/renderer/src/runtime/sync-runtime-graph/graph-state.ts b/src/renderer/src/runtime/sync-runtime-graph/graph-state.ts
index 2c8d88dfcae..7b19069414a 100644
--- a/src/renderer/src/runtime/sync-runtime-graph/graph-state.ts
+++ b/src/renderer/src/runtime/sync-runtime-graph/graph-state.ts
@@ -67,7 +67,6 @@ export const graphState = {
   cachedOpenFilesProjection: null as OpenFilesProjectionCache | null,
   cachedBrowserWorkspacesProjection: null as BrowserWorkspacesProjectionCache | null,
   cachedBrowserPagesProjection: null as BrowserPagesProjectionCache | null,
-  cachedMobileSessionAgentStatus: null as MobileSessionAgentStatusCache | null,
   cachedOpenFileIndexesSource: null as AppState['openFiles'] | null,
   cachedOpenFileIndexes: null as OpenFileIndexes | null,
   cachedEditorDraftHashes: null as EditorDraftHashCache | null,
@@ -77,11 +76,22 @@ export const graphState = {
   hasCachedMobileTerminalTheme: false
 }
 
+// Module-local rather than `graphState` fields: a nullable field on that object literal needs an
+// `as` cast, which the changed-code casting gate rejects.
 let terminalTabOwnershipIndexCache: TerminalTabOwnershipIndex | null = null
+let mobileSessionAgentStatusCache: MobileSessionAgentStatusCache | null = null
+
+export function getMobileSessionAgentStatusCache(): MobileSessionAgentStatusCache | null {
+  return mobileSessionAgentStatusCache
+}
+
+export function setMobileSessionAgentStatusCache(cache: MobileSessionAgentStatusCache): void {
+  mobileSessionAgentStatusCache = cache
+}
 
 export function resetRuntimeGraphSliceScanCaches(): void {
   terminalTabOwnershipIndexCache = null
-  graphState.cachedMobileSessionAgentStatus = null
+  mobileSessionAgentStatusCache = null
 }
 
 export function registeredTerminalTabKey(
diff --git a/src/renderer/src/runtime/sync-runtime-graph/mobile-session-inputs.ts b/src/renderer/src/runtime/sync-runtime-graph/mobile-session-inputs.ts
index 4a54beb9ef7..a96e38affe1 100644
--- a/src/renderer/src/runtime/sync-runtime-graph/mobile-session-inputs.ts
+++ b/src/renderer/src/runtime/sync-runtime-graph/mobile-session-inputs.ts
@@ -10,8 +10,10 @@ import {
   EMPTY_WORKTREE_TERMINAL_TABS,
   EMPTY_WORKTREE_UNIFIED_TABS,
   EMPTY_LAYOUT_BY_WORKTREE,
+  getMobileSessionAgentStatusCache,
   getTerminalTabOwnershipIndex,
-  graphState
+  graphState,
+  setMobileSessionAgentStatusCache
 } from './graph-state'
 import type {
   MobileSessionAgentStatusByWorktree,
@@ -70,7 +72,7 @@ export function buildMobileSessionAgentStatusByWorktree(
   agentStatusByPaneKey: AppState['agentStatusByPaneKey'],
   tabsByWorktree: AppState['tabsByWorktree']
 ): MobileSessionAgentStatusByWorktree {
-  const cached = graphState.cachedMobileSessionAgentStatus
+  const cached = getMobileSessionAgentStatusCache()
   if (cached?.agentStatusSource === agentStatusByPaneKey && cached.tabsSource === tabsByWorktree) {
     return cached.byWorktreeId
   }
@@ -101,11 +103,11 @@ export function buildMobileSessionAgentStatusByWorktree(
       byWorktreeId.set(worktreeId, previousBucket)
     }
   }
-  graphState.cachedMobileSessionAgentStatus = {
+  setMobileSessionAgentStatusCache({
     agentStatusSource: agentStatusByPaneKey,
     tabsSource: tabsByWorktree,
     byWorktreeId
-  }
+  })
   return byWorktreeId
 }