diff --git a/packages/next/src/client/components/router-reducer/ppr-navigations.ts b/packages/next/src/client/components/router-reducer/ppr-navigations.ts
index 680fb13766ef78..bffd3112b879ab 100644
--- a/packages/next/src/client/components/router-reducer/ppr-navigations.ts
+++ b/packages/next/src/client/components/router-reducer/ppr-navigations.ts
@@ -2,6 +2,7 @@ import type {
   CacheNodeSeedData,
   FlightRouterState,
   FlightSegmentPath,
+  RefreshState,
 } from '../../../shared/lib/app-router-types'
 import type {
   ChildSegmentMap,
@@ -51,7 +52,7 @@ export type NavigationTask = {
   // The URL that should be used to fetch the dynamic data. This is only set
   // when the segment cannot be refetched from the current route, because it's
   // part of a "default" parallel slot that was reused during a navigation.
-  refreshUrl: string | null
+  refreshState: RefreshState | null
   children: Map<string, NavigationTask> | null
 }
 
@@ -175,6 +176,7 @@ export function createInitialCacheNodeForHydration(
 export function startPPRNavigation(
   navigatedAt: number,
   oldUrl: URL,
+  oldRenderedSearch: string,
   oldCacheNode: CacheNode | null,
   oldRouterState: FlightRouterState,
   newRouterState: FlightRouterState,
@@ -189,7 +191,11 @@ export function startPPRNavigation(
 ): NavigationTask | null {
   const didFindRootLayout = false
   const parentNeedsDynamicRequest = false
-  const parentRefreshUrl = null
+  const parentRefreshState = null
+  const oldRootRefreshState: RefreshState = [
+    createHrefFromUrl(oldUrl),
+    oldRenderedSearch,
+  ]
   return updateCacheNodeOnNavigation(
     navigatedAt,
     oldUrl,
@@ -207,7 +213,8 @@ export function startPPRNavigation(
     null,
     null,
     parentNeedsDynamicRequest,
-    parentRefreshUrl,
+    oldRootRefreshState,
+    parentRefreshState,
     accumulation
   )
 }
@@ -229,7 +236,8 @@ function updateCacheNodeOnNavigation(
   parentSegmentPath: FlightSegmentPath | null,
   parentParallelRouteKey: string | null,
   parentNeedsDynamicRequest: boolean,
-  parentRefreshUrl: string | null,
+  oldRootRefreshState: RefreshState,
+  parentRefreshState: RefreshState | null,
   accumulation: NavigationRequestAccumulation
 ): NavigationTask | null {
   // Check if this segment matches the one in the previous route.
@@ -441,20 +449,20 @@ function updateCacheNodeOnNavigation(
   // current route; it may have been reused from an older route. If so,
   // we need to fetch its data from the old route's URL rather than current
   // route's URL. Keep track of this as we traverse the tree.
-  const href = newRouterState[2]
-  const refreshUrl =
-    typeof href === 'string' && newRouterState[3] === 'refresh'
+  const maybeRefreshState = newRouterState[2]
+  const refreshState =
+    maybeRefreshState !== undefined && maybeRefreshState !== null
       ? // This segment is not present in the current route. Track its
         // refresh URL as we continue traversing the tree.
-        href
+        maybeRefreshState
       : // Inherit the refresh URL from the parent.
-        parentRefreshUrl
+        parentRefreshState
 
   // If this segment itself needs to fetch new data from the server, then by
   // definition it is being refreshed. Track its refresh URL so we know which
   // URL to request the data from.
-  if (needsDynamicRequest && refreshUrl !== null) {
-    accumulateRefreshUrl(accumulation, refreshUrl)
+  if (needsDynamicRequest && refreshState !== null) {
+    accumulateRefreshUrl(accumulation, refreshState)
   }
 
   // As we diff the trees, we may sometimes modify (copy-on-write, not mutate)
@@ -524,7 +532,7 @@ function updateCacheNodeOnNavigation(
       // a soft navigation; instead, the client reuses whatever segment was
       // already active in that slot on the previous route.
       newRouterStateChild = reuseActiveSegmentInDefaultSlot(
-        oldUrl,
+        oldRootRefreshState,
         oldRouterStateChild
       )
       newSegmentChild = newRouterStateChild[0]
@@ -561,7 +569,8 @@ function updateCacheNodeOnNavigation(
       segmentPath,
       parallelRouteKey,
       parentNeedsDynamicRequest || needsDynamicRequest,
-      refreshUrl,
+      oldRootRefreshState,
+      refreshState,
       accumulation
     )
 
@@ -618,7 +627,7 @@ function updateCacheNodeOnNavigation(
       childNeedsDynamicRequest,
       parentNeedsDynamicRequest
     ),
-    refreshUrl,
+    refreshState,
     children: taskChildren,
   }
 }
@@ -923,7 +932,7 @@ function createCacheNodeOnNavigation(
     ),
     // This route is not part of the current tree, so there's no reason to
     // track the refresh URL.
-    refreshUrl: null,
+    refreshState: null,
     children: taskChildren,
   }
 }
@@ -986,7 +995,7 @@ function createDynamicRequestTree(
 
 function accumulateRefreshUrl(
   accumulation: NavigationRequestAccumulation,
-  refreshUrl: string
+  refreshState: RefreshState
 ) {
   // This is a refresh navigation, and we're inside a "default" slot that's
   // not part of the current route; it was reused from an older route. In
@@ -998,6 +1007,7 @@ function accumulateRefreshUrl(
   // we don't do it immediately here is so we can deduplicate multiple
   // instances of the same URL into a single request. See
   // listenForDynamicRequest for more details.
+  const refreshUrl = refreshState[0]
   const separateRefreshUrls = accumulation.separateRefreshUrls
   if (separateRefreshUrls === null) {
     accumulation.separateRefreshUrls = new Set([refreshUrl])
@@ -1007,7 +1017,7 @@ function accumulateRefreshUrl(
 }
 
 function reuseActiveSegmentInDefaultSlot(
-  oldUrl: URL,
+  oldRootRefreshState: RefreshState,
   oldRouterState: FlightRouterState
 ): FlightRouterState {
   // This is a "default" segment. These are never sent by the server during a
@@ -1015,26 +1025,22 @@ function reuseActiveSegmentInDefaultSlot(
   // active in that slot on the previous route. This means if we later need to
   // refresh the segment, it will have to be refetched from the previous route's
   // URL. We store it in the Flight Router State.
-  //
-  // TODO: We also mark the segment with a "refresh" marker but I think we can
-  // get rid of that eventually by making sure we only add URLs to page segments
-  // that are reused. Then the presence of the URL alone is enough.
   let reusedRouterState
 
-  const oldRefreshMarker = oldRouterState[3]
-  if (oldRefreshMarker === 'refresh') {
+  const oldRefreshState = oldRouterState[2]
+  if (oldRefreshState !== undefined && oldRefreshState !== null) {
     // This segment was already reused from an even older route. Keep its
-    // existing URL and refresh marker.
+    // existing URL and refresh state.
     reusedRouterState = oldRouterState
   } else {
-    // This segment was not previously reused, and it's not on the new route.
-    // So it must have been delivered in the old route.
+    // Since this route didn't already have a refresh state, it must have been
+    // reachable from the root of the old route. So we use the refresh state
+    // that represents the old route.
     reusedRouterState = patchRouterStateWithNewChildren(
       oldRouterState,
       oldRouterState[1]
     )
-    reusedRouterState[2] = createHrefFromUrl(oldUrl)
-    reusedRouterState[3] = 'refresh'
+    reusedRouterState[2] = oldRootRefreshState
   }
 
   return reusedRouterState
@@ -1631,7 +1637,7 @@ function abortRemainingPendingTasks(
     //
     // When this happens, we treat this the same as a refresh(). The entire
     // tree will be re-rendered from the root.
-    if (task.refreshUrl === null) {
+    if (task.refreshState === null) {
       // Trigger a "soft" refresh. Essentially the same as calling `refresh()`
       // in a Server Action.
       exitStatus = NavigationTaskExitStatus.SoftRetry
diff --git a/packages/next/src/client/components/router-reducer/reducers/navigate-reducer.ts b/packages/next/src/client/components/router-reducer/reducers/navigate-reducer.ts
index 9484c7702df103..f2f4742bb8e728 100644
--- a/packages/next/src/client/components/router-reducer/reducers/navigate-reducer.ts
+++ b/packages/next/src/client/components/router-reducer/reducers/navigate-reducer.ts
@@ -162,9 +162,11 @@ export function navigateReducer(
   // implementation. Eventually we'll rewrite the router reducer to a
   // state machine.
   const currentUrl = new URL(state.canonicalUrl, location.origin)
+  const currentRenderedSearch = state.renderedSearch
   const result = navigateUsingSegmentCache(
     url,
     currentUrl,
+    currentRenderedSearch,
     state.cache,
     state.tree,
     state.nextUrl,
diff --git a/packages/next/src/client/components/router-reducer/reducers/refresh-reducer.ts b/packages/next/src/client/components/router-reducer/reducers/refresh-reducer.ts
index ada23b8920b6bd..d9940aeca0fdaa 100644
--- a/packages/next/src/client/components/router-reducer/reducers/refresh-reducer.ts
+++ b/packages/next/src/client/components/router-reducer/reducers/refresh-reducer.ts
@@ -36,6 +36,7 @@ export function refreshDynamicData(
   // existing dynamic data (including in shared layouts) is re-fetched.
   const currentCanonicalUrl = state.canonicalUrl
   const currentUrl = new URL(currentCanonicalUrl, location.origin)
+  const currentRenderedSearch = state.renderedSearch
   const currentFlightRouterState = state.tree
   const shouldScroll = true
 
@@ -53,6 +54,7 @@ export function refreshDynamicData(
     currentCanonicalUrl,
     navigationSeed,
     currentUrl,
+    currentRenderedSearch,
     state.cache,
     currentFlightRouterState,
     freshnessPolicy,
diff --git a/packages/next/src/client/components/router-reducer/reducers/restore-reducer.ts b/packages/next/src/client/components/router-reducer/reducers/restore-reducer.ts
index 9484feba57bee1..f580b84f4912ff 100644
--- a/packages/next/src/client/components/router-reducer/reducers/restore-reducer.ts
+++ b/packages/next/src/client/components/router-reducer/reducers/restore-reducer.ts
@@ -50,6 +50,7 @@ export function restoreReducer(
   const task = startPPRNavigation(
     now,
     currentUrl,
+    state.renderedSearch,
     state.cache,
     state.tree,
     treeToRestore,
diff --git a/packages/next/src/client/components/router-reducer/reducers/server-action-reducer.ts b/packages/next/src/client/components/router-reducer/reducers/server-action-reducer.ts
index 562ed32962ed06..ef2a4b50f5e42a 100644
--- a/packages/next/src/client/components/router-reducer/reducers/server-action-reducer.ts
+++ b/packages/next/src/client/components/router-reducer/reducers/server-action-reducer.ts
@@ -382,6 +382,7 @@ export function serverActionReducer(
       // If there was no redirect, then the target URL is the same as the
       // current URL.
       const currentUrl = new URL(state.canonicalUrl, location.origin)
+      const currentRenderedSearch = state.renderedSearch
       const redirectUrl =
         redirectLocation !== undefined ? redirectLocation : currentUrl
       const currentFlightRouterState = state.tree
@@ -425,6 +426,7 @@ export function serverActionReducer(
             redirectCanonicalUrl,
             navigationSeed,
             currentUrl,
+            currentRenderedSearch,
             state.cache,
             currentFlightRouterState,
             freshnessPolicy,
@@ -446,6 +448,7 @@ export function serverActionReducer(
       const result = navigateUsingSegmentCache(
         redirectUrl,
         currentUrl,
+        currentRenderedSearch,
         state.cache,
         currentFlightRouterState,
         nextUrl,
diff --git a/packages/next/src/client/components/router-reducer/reducers/server-patch-reducer.ts b/packages/next/src/client/components/router-reducer/reducers/server-patch-reducer.ts
index 977186b42bf050..697498f09f112d 100644
--- a/packages/next/src/client/components/router-reducer/reducers/server-patch-reducer.ts
+++ b/packages/next/src/client/components/router-reducer/reducers/server-patch-reducer.ts
@@ -30,6 +30,7 @@ export function serverPatchReducer(
     return handleExternalUrl(state, mutable, retryUrl.href, false)
   }
   const currentUrl = new URL(state.canonicalUrl, location.origin)
+  const currentRenderedSearch = state.renderedSearch
   if (action.previousTree !== state.tree) {
     // There was another, more recent navigation since the once that
     // mismatched. We can abort the retry, but we still need to refresh the
@@ -50,6 +51,7 @@ export function serverPatchReducer(
     retryCanonicalUrl,
     retrySeed,
     currentUrl,
+    currentRenderedSearch,
     state.cache,
     state.tree,
     FreshnessPolicy.RefreshAll,
diff --git a/packages/next/src/client/components/router-reducer/router-reducer-types.ts b/packages/next/src/client/components/router-reducer/router-reducer-types.ts
index 02feeb2379a032..2d579ca0e1ea15 100644
--- a/packages/next/src/client/components/router-reducer/router-reducer-types.ts
+++ b/packages/next/src/client/components/router-reducer/router-reducer-types.ts
@@ -222,7 +222,17 @@ export type AppRouterState = {
    * - This is the url you see in the browser.
    */
   canonicalUrl: string
+
+  /**
+   * The search query observed by the server during rendering. This may be
+   * different from the canonical URL's search query if the server performed
+   * a rewrite. Even though a client component won't observe this (unless it
+   * were passed from a Server component), the client router needs to know this
+   * so it can properly cache segment data; it'ss part of a page segment's
+   * cache key.
+   */
   renderedSearch: string
+
   /**
    * The underlying "url" representing the UI state, which is used for intercepting routes.
    */
diff --git a/packages/next/src/client/components/segment-cache/navigation.ts b/packages/next/src/client/components/segment-cache/navigation.ts
index 3422fffb1bd6be..bfc3c2bbedac96 100644
--- a/packages/next/src/client/components/segment-cache/navigation.ts
+++ b/packages/next/src/client/components/segment-cache/navigation.ts
@@ -70,6 +70,7 @@ export type NavigationResult =
 export function navigate(
   url: URL,
   currentUrl: URL,
+  currentRenderedSearch: string,
   currentCacheNode: CacheNode | null,
   currentFlightRouterState: FlightRouterState,
   nextUrl: string | null,
@@ -122,6 +123,7 @@ export function navigate(
       now,
       url,
       currentUrl,
+      currentRenderedSearch,
       nextUrl,
       isSamePageNavigation,
       currentCacheNode,
@@ -166,6 +168,7 @@ export function navigate(
         now,
         url,
         currentUrl,
+        currentRenderedSearch,
         nextUrl,
         isSamePageNavigation,
         currentCacheNode,
@@ -193,6 +196,7 @@ export function navigate(
       now,
       url,
       currentUrl,
+      currentRenderedSearch,
       nextUrl,
       currentCacheNode,
       currentFlightRouterState,
@@ -209,6 +213,7 @@ export function navigateToSeededRoute(
   canonicalUrl: string,
   navigationSeed: NavigationSeed,
   currentUrl: URL,
+  currentRenderedSearch: string,
   currentCacheNode: CacheNode | null,
   currentFlightRouterState: FlightRouterState,
   freshnessPolicy: FreshnessPolicy,
@@ -225,6 +230,7 @@ export function navigateToSeededRoute(
   const task = startPPRNavigation(
     now,
     currentUrl,
+    currentRenderedSearch,
     currentCacheNode,
     currentFlightRouterState,
     navigationSeed.tree,
@@ -259,6 +265,7 @@ function navigateUsingPrefetchedRouteTree(
   now: number,
   url: URL,
   currentUrl: URL,
+  currentRenderedSearch: string,
   nextUrl: string | null,
   isSamePageNavigation: boolean,
   currentCacheNode: CacheNode | null,
@@ -287,6 +294,7 @@ function navigateUsingPrefetchedRouteTree(
   const task = startPPRNavigation(
     now,
     currentUrl,
+    currentRenderedSearch,
     currentCacheNode,
     currentFlightRouterState,
     prefetchFlightRouterState,
@@ -483,6 +491,7 @@ async function navigateDynamicallyWithNoPrefetch(
   now: number,
   url: URL,
   currentUrl: URL,
+  currentRenderedSearch: string,
   nextUrl: string | null,
   currentCacheNode: CacheNode | null,
   currentFlightRouterState: FlightRouterState,
@@ -558,6 +567,7 @@ async function navigateDynamicallyWithNoPrefetch(
     createHrefFromUrl(canonicalUrl),
     navigationSeed,
     currentUrl,
+    currentRenderedSearch,
     currentCacheNode,
     currentFlightRouterState,
     freshnessPolicy,
diff --git a/packages/next/src/client/flight-data-helpers.test.ts b/packages/next/src/client/flight-data-helpers.test.ts
index b8765f6df50a9b..fed137b6dff220 100644
--- a/packages/next/src/client/flight-data-helpers.test.ts
+++ b/packages/next/src/client/flight-data-helpers.test.ts
@@ -10,8 +10,8 @@ describe('prepareFlightRouterStateForRequest', () => {
       const flightRouterState: FlightRouterState = [
         '__PAGE__?{"sensitive":"data"}',
         {},
-        '/some/url',
-        'refresh',
+        ['/some/url', ''],
+        'refetch',
         true,
         1,
       ]
@@ -61,14 +61,13 @@ describe('prepareFlightRouterStateForRequest', () => {
       const flightRouterState: FlightRouterState = [
         'segment',
         {},
-        '/sensitive/url/path',
-        null,
+        ['/sensitive/url/path', ''],
       ]
 
       const result = prepareFlightRouterStateForRequest(flightRouterState)
       const decoded = JSON.parse(decodeURIComponent(result))
 
-      expect(decoded[2]).toBeNull()
+      expect(decoded[2]).toBeUndefined()
     })
   })
 
@@ -77,7 +76,7 @@ describe('prepareFlightRouterStateForRequest', () => {
       const flightRouterState: FlightRouterState = [
         'segment',
         {},
-        '/url',
+        ['/url', ''],
         'refetch',
       ]
 
@@ -91,7 +90,7 @@ describe('prepareFlightRouterStateForRequest', () => {
       const flightRouterState: FlightRouterState = [
         'segment',
         {},
-        '/url',
+        ['/url', ''],
         'inside-shared-layout',
       ]
 
@@ -101,27 +100,27 @@ describe('prepareFlightRouterStateForRequest', () => {
       expect(decoded[3]).toBe('inside-shared-layout')
     })
 
-    it('should strip "refresh" marker (client-only)', () => {
-      const flightRouterState: FlightRouterState = [
-        'segment',
-        {},
-        '/url',
-        'refresh',
-      ]
+    it('should strip "refresh" state (client-only)', () => {
+      const flightRouterState: FlightRouterState = ['segment', {}, ['/url', '']]
 
       const result = prepareFlightRouterStateForRequest(flightRouterState)
       const decoded = JSON.parse(decodeURIComponent(result))
 
-      expect(decoded[3]).toBeNull()
+      expect(decoded[2]).toBeUndefined()
     })
 
     it('should strip null refresh marker', () => {
-      const flightRouterState: FlightRouterState = ['segment', {}, '/url', null]
+      const flightRouterState: FlightRouterState = [
+        'segment',
+        {},
+        ['/url', ''],
+        null,
+      ]
 
       const result = prepareFlightRouterStateForRequest(flightRouterState)
       const decoded = JSON.parse(decodeURIComponent(result))
 
-      expect(decoded[3]).toBeNull()
+      expect(decoded[3]).toBeUndefined()
     })
   })
 
@@ -181,8 +180,8 @@ describe('prepareFlightRouterStateForRequest', () => {
       expect(decoded).toEqual([
         'segment',
         {},
-        null, // URL
-        null, // refresh marker
+        // URL
+        // refresh marker
       ])
     })
   })
@@ -192,15 +191,10 @@ describe('prepareFlightRouterStateForRequest', () => {
       const flightRouterState: FlightRouterState = [
         'parent',
         {
-          children: [
-            '__PAGE__?{"nested":"param"}',
-            {},
-            '/nested/url',
-            'refresh',
-          ],
-          modal: ['modal-segment', {}, '/modal/url', 'refetch'],
+          children: ['__PAGE__?{"nested":"param"}', {}, ['/nested/url', '']],
+          modal: ['modal-segment', {}, ['/modal/url', ''], 'refetch'],
         },
-        '/parent/url',
+        ['/parent/url', ''],
         'inside-shared-layout',
       ]
 
@@ -213,8 +207,8 @@ describe('prepareFlightRouterStateForRequest', () => {
           children: [
             '__PAGE__', // search params stripped
             {},
-            null, // URL stripped
-            null, // 'refresh' marker stripped
+            // URL stripped
+            // 'refresh' marker stripped
           ],
           modal: [
             'modal-segment',
@@ -238,7 +232,7 @@ describe('prepareFlightRouterStateForRequest', () => {
               children: [
                 '__PAGE__?{"deep":"nesting"}',
                 {},
-                '/deep/url',
+                ['/deep/url', ''],
                 'refetch',
               ],
             },
@@ -266,20 +260,20 @@ describe('prepareFlightRouterStateForRequest', () => {
               modal: [
                 '__PAGE__?{"modalParam":"data"}',
                 {},
-                '/modal/path',
-                'refresh',
+                ['/modal/path', ''],
+                null,
                 false,
                 HasLoadingBoundary.SegmentHasLoadingBoundary,
               ],
             },
-            '/dashboard/url',
+            ['/dashboard/url', ''],
             'refetch',
             true,
             1,
           ],
-          sidebar: [['slug', 'user-123', 'd'], {}, '/sidebar/url', null],
+          sidebar: [['slug', 'user-123', 'd'], {}, ['/sidebar/url', ''], null],
         },
-        '/main/url',
+        ['/main/url', ''],
         'inside-shared-layout',
         true,
         1,
@@ -312,8 +306,8 @@ describe('prepareFlightRouterStateForRequest', () => {
       // Sidebar route (dynamic segment) checks
       const sidebarRoute = decoded[1].sidebar
       expect(sidebarRoute[0]).toEqual(['slug', 'user-123', 'd']) // dynamic segment preserved
-      expect(sidebarRoute[2]).toBeNull() // URL stripped
-      expect(sidebarRoute[3]).toBeNull() // null marker remains null
+      expect(sidebarRoute[2]).toBeUndefined() // URL stripped
+      expect(sidebarRoute[3]).toBeUndefined() // null marker stripped
     })
   })
 })
diff --git a/packages/next/src/client/flight-data-helpers.ts b/packages/next/src/client/flight-data-helpers.ts
index dde9ed5a9e5bfd..2b36ba7141745c 100644
--- a/packages/next/src/client/flight-data-helpers.ts
+++ b/packages/next/src/client/flight-data-helpers.ts
@@ -244,7 +244,7 @@ function stripClientOnlyDataFromFlightRouterState(
   const [
     segment,
     parallelRoutes,
-    _url, // Intentionally unused - URLs are client-only
+    _refreshState, // Intentionally unused - URLs are client-only
     refreshMarker,
     isRootLayout,
     hasLoadingBoundary,
@@ -261,12 +261,11 @@ function stripClientOnlyDataFromFlightRouterState(
       stripClientOnlyDataFromFlightRouterState(childState)
   }
 
-  const result: FlightRouterState = [
-    cleanedSegment,
-    cleanedParallelRoutes,
-    null, // URLs omitted - server reconstructs paths from segments
-    shouldPreserveRefreshMarker(refreshMarker) ? refreshMarker : null,
-  ]
+  const result: FlightRouterState = [cleanedSegment, cleanedParallelRoutes]
+  if (refreshMarker) {
+    result[2] = null // null slightly more compact than undefined
+    result[3] = refreshMarker
+  }
 
   // Append optional fields if present
   if (isRootLayout !== undefined) {
@@ -276,6 +275,7 @@ function stripClientOnlyDataFromFlightRouterState(
     result[5] = hasLoadingBoundary
   }
 
+  // Everything else is used only by the client and is not needed for requests.
   return result
 }
 
@@ -292,14 +292,3 @@ function stripSearchParamsFromPageSegment(segment: Segment): Segment {
   }
   return segment
 }
-
-/**
- * Determines whether the refresh marker should be sent to the server
- * Client-only markers like 'refresh' are stripped, while server-needed markers
- * like 'refetch' and 'inside-shared-layout' are preserved.
- */
-function shouldPreserveRefreshMarker(
-  refreshMarker: FlightRouterState[3]
-): boolean {
-  return Boolean(refreshMarker && refreshMarker !== 'refresh')
-}
diff --git a/packages/next/src/server/app-render/types.ts b/packages/next/src/server/app-render/types.ts
index d98b94b864f75c..0428fb3ab25588 100644
--- a/packages/next/src/server/app-render/types.ts
+++ b/packages/next/src/server/app-render/types.ts
@@ -61,7 +61,7 @@ export const flightRouterStateSchema: s.Describe<any> = s.tuple([
     s.string(),
     s.lazy(() => flightRouterStateSchema)
   ),
-  s.optional(s.nullable(s.string())),
+  s.optional(s.nullable(s.tuple([s.string(), s.string()]))),
   s.optional(
     s.nullable(
       s.union([
diff --git a/packages/next/src/shared/lib/app-router-types.ts b/packages/next/src/shared/lib/app-router-types.ts
index 60927b3d5ec517..d8b2686a97d965 100644
--- a/packages/next/src/shared/lib/app-router-types.ts
+++ b/packages/next/src/shared/lib/app-router-types.ts
@@ -108,17 +108,11 @@ export type Segment =
 export type FlightRouterState = [
   segment: Segment,
   parallelRoutes: { [parallelRouterKey: string]: FlightRouterState },
-  url?: string | null,
+  refreshState?: RefreshState | null,
   /**
-   * "refresh" and "refetch", despite being similarly named, have different
-   * semantics:
    * - "refetch" is used during a request to inform the server where rendering
    *   should start from.
    *
-   * - "refresh" is used by the client to mark that a segment should re-fetch the
-   *   data from the server for the current segment. It uses the "url" property
-   *   above to determine where to fetch from.
-   *
    * - "inside-shared-layout" is used during a prefetch request to inform the
    *   server that even if the segment matches, it should be treated as if it's
    *   within the "new" part of a navigation — inside the shared layout. If
@@ -137,12 +131,7 @@ export type FlightRouterState = [
    *   make sense for the client to send a FlightRouterState, since this type is
    *   overloaded with concerns.
    */
-  refresh?:
-    | 'refetch'
-    | 'refresh'
-    | 'inside-shared-layout'
-    | 'metadata-only'
-    | null,
+  refresh?: 'refetch' | 'inside-shared-layout' | 'metadata-only' | null,
   isRootLayout?: boolean,
   /**
    * Only present when responding to a tree prefetch request. Indicates whether
@@ -152,6 +141,18 @@ export type FlightRouterState = [
   hasLoadingBoundary?: HasLoadingBoundary,
 ]
 
+/**
+ * When rendering a parallel route, some of the parallel paths may not match
+ * the current URL. In that case, the Next client has to render something,
+ * so it will render whichever was the last route to match that slot. We use
+ * this type to track when this has happened. It's a tuple of the original
+ * URL that was used to fetch the segment, and the (possibly rewritten) search
+ * query that was rendered by the server. The URL is needed when performing
+ * a refresh of the segment, and the search query is needed for looking up
+ * matching entries in the segment cache.
+ */
+export type RefreshState = [url: string, renderedSearch: string]
+
 export const enum HasLoadingBoundary {
   // There is a loading boundary in this particular segment
   SegmentHasLoadingBoundary = 1,