diff --git a/packages/react-reconciler/src/ReactFiberLane.new.js b/packages/react-reconciler/src/ReactFiberLane.new.js
index 5a71b4ce489e3..59e04b1865d4d 100644
--- a/packages/react-reconciler/src/ReactFiberLane.new.js
+++ b/packages/react-reconciler/src/ReactFiberLane.new.js
@@ -11,25 +11,6 @@ import type {FiberRoot} from './ReactInternalTypes';
 
 // TODO: Ideally these types would be opaque but that doesn't work well with
 // our reconciler fork infra, since these leak into non-reconciler packages.
-export type LanePriority =
-  | 0
-  | 1
-  | 2
-  | 3
-  | 4
-  | 5
-  | 6
-  | 7
-  | 8
-  | 9
-  | 10
-  | 11
-  | 12
-  | 13
-  | 14
-  | 15
-  | 16
-  | 17;
 
 export type Lanes = number;
 export type Lane = number;
@@ -44,28 +25,6 @@ import {
 import {isDevToolsPresent} from './ReactFiberDevToolsHook.new';
 import {ConcurrentUpdatesByDefaultMode, NoMode} from './ReactTypeOfMode';
 
-export const SyncLanePriority: LanePriority = 12;
-
-const InputContinuousHydrationLanePriority: LanePriority = 11;
-export const InputContinuousLanePriority: LanePriority = 10;
-
-const DefaultHydrationLanePriority: LanePriority = 9;
-export const DefaultLanePriority: LanePriority = 8;
-
-const TransitionHydrationPriority: LanePriority = 7;
-export const TransitionPriority: LanePriority = 6;
-
-const RetryLanePriority: LanePriority = 5;
-
-const SelectiveHydrationLanePriority: LanePriority = 4;
-
-const IdleHydrationLanePriority: LanePriority = 3;
-export const IdleLanePriority: LanePriority = 2;
-
-const OffscreenLanePriority: LanePriority = 1;
-
-export const NoLanePriority: LanePriority = 0;
-
 // Lane values below should be kept in sync with getLabelsForLanes(), used by react-devtools-scheduling-profiler.
 // If those values are changed that package should be rebuilt and redeployed.
 
@@ -169,29 +128,19 @@ export const NoTimestamp = -1;
 let nextTransitionLane: Lane = TransitionLane1;
 let nextRetryLane: Lane = RetryLane1;
 
-// "Registers" used to "return" multiple values
-// Used by getHighestPriorityLanes and getNextLanes:
-let return_highestLanePriority: LanePriority = DefaultLanePriority;
-
 function getHighestPriorityLanes(lanes: Lanes | Lane): Lanes {
   switch (getHighestPriorityLane(lanes)) {
     case SyncLane:
-      return_highestLanePriority = SyncLanePriority;
       return SyncLane;
     case InputContinuousHydrationLane:
-      return_highestLanePriority = InputContinuousHydrationLanePriority;
       return InputContinuousHydrationLane;
     case InputContinuousLane:
-      return_highestLanePriority = InputContinuousLanePriority;
       return InputContinuousLane;
     case DefaultHydrationLane:
-      return_highestLanePriority = DefaultHydrationLanePriority;
       return DefaultHydrationLane;
     case DefaultLane:
-      return_highestLanePriority = DefaultLanePriority;
       return DefaultLane;
     case TransitionHydrationLane:
-      return_highestLanePriority = TransitionHydrationPriority;
       return TransitionHydrationLane;
     case TransitionLane1:
     case TransitionLane2:
@@ -209,26 +158,20 @@ function getHighestPriorityLanes(lanes: Lanes | Lane): Lanes {
     case TransitionLane14:
     case TransitionLane15:
     case TransitionLane16:
-      return_highestLanePriority = TransitionPriority;
       return lanes & TransitionLanes;
     case RetryLane1:
     case RetryLane2:
     case RetryLane3:
     case RetryLane4:
     case RetryLane5:
-      return_highestLanePriority = RetryLanePriority;
       return lanes & RetryLanes;
     case SelectiveHydrationLane:
-      return_highestLanePriority = SelectiveHydrationLanePriority;
       return SelectiveHydrationLane;
     case IdleHydrationLane:
-      return_highestLanePriority = IdleHydrationLanePriority;
       return IdleHydrationLane;
     case IdleLane:
-      return_highestLanePriority = IdleLanePriority;
       return IdleLane;
     case OffscreenLane:
-      return_highestLanePriority = OffscreenLanePriority;
       return OffscreenLane;
     default:
       if (__DEV__) {
@@ -237,7 +180,6 @@ function getHighestPriorityLanes(lanes: Lanes | Lane): Lanes {
         );
       }
       // This shouldn't be reachable, but as a fallback, return the entire bitmask.
-      return_highestLanePriority = DefaultLanePriority;
       return lanes;
   }
 }
@@ -246,12 +188,10 @@ export function getNextLanes(root: FiberRoot, wipLanes: Lanes): Lanes {
   // Early bailout if there's no pending work left.
   const pendingLanes = root.pendingLanes;
   if (pendingLanes === NoLanes) {
-    return_highestLanePriority = NoLanePriority;
     return NoLanes;
   }
 
   let nextLanes = NoLanes;
-  let nextLanePriority = NoLanePriority;
 
   const suspendedLanes = root.suspendedLanes;
   const pingedLanes = root.pingedLanes;
@@ -263,12 +203,10 @@ export function getNextLanes(root: FiberRoot, wipLanes: Lanes): Lanes {
     const nonIdleUnblockedLanes = nonIdlePendingLanes & ~suspendedLanes;
     if (nonIdleUnblockedLanes !== NoLanes) {
       nextLanes = getHighestPriorityLanes(nonIdleUnblockedLanes);
-      nextLanePriority = return_highestLanePriority;
     } else {
       const nonIdlePingedLanes = nonIdlePendingLanes & pingedLanes;
       if (nonIdlePingedLanes !== NoLanes) {
         nextLanes = getHighestPriorityLanes(nonIdlePingedLanes);
-        nextLanePriority = return_highestLanePriority;
       }
     }
   } else {
@@ -276,11 +214,9 @@ export function getNextLanes(root: FiberRoot, wipLanes: Lanes): Lanes {
     const unblockedLanes = pendingLanes & ~suspendedLanes;
     if (unblockedLanes !== NoLanes) {
       nextLanes = getHighestPriorityLanes(unblockedLanes);
-      nextLanePriority = return_highestLanePriority;
     } else {
       if (pingedLanes !== NoLanes) {
         nextLanes = getHighestPriorityLanes(pingedLanes);
-        nextLanePriority = return_highestLanePriority;
       }
     }
   }
@@ -314,8 +250,6 @@ export function getNextLanes(root: FiberRoot, wipLanes: Lanes): Lanes {
     ) {
       // Keep working on the existing in-progress tree. Do not interrupt.
       return wipLanes;
-    } else {
-      return_highestLanePriority = nextLanePriority;
     }
   }
 
@@ -511,9 +445,6 @@ export function getLanesToRetrySynchronouslyOnError(root: FiberRoot): Lanes {
   return NoLanes;
 }
 
-export function returnNextLanesPriority() {
-  return return_highestLanePriority;
-}
 export function includesNonIdleWork(lanes: Lanes) {
   return (lanes & NonIdleLanes) !== NoLanes;
 }
@@ -623,13 +554,6 @@ export function higherPriorityLane(a: Lane, b: Lane) {
   return a !== NoLane && a < b ? a : b;
 }
 
-export function higherLanePriority(
-  a: LanePriority,
-  b: LanePriority,
-): LanePriority {
-  return a !== NoLanePriority && a > b ? a : b;
-}
-
 export function createLaneMap<T>(initial: T): LaneMap<T> {
   // Intentionally pushing one by one.
   // https://v8.dev/blog/elements-kinds#avoid-creating-holes
diff --git a/packages/react-reconciler/src/ReactFiberLane.old.js b/packages/react-reconciler/src/ReactFiberLane.old.js
index d3443dbe24d00..458d3ec6290ec 100644
--- a/packages/react-reconciler/src/ReactFiberLane.old.js
+++ b/packages/react-reconciler/src/ReactFiberLane.old.js
@@ -11,25 +11,6 @@ import type {FiberRoot} from './ReactInternalTypes';
 
 // TODO: Ideally these types would be opaque but that doesn't work well with
 // our reconciler fork infra, since these leak into non-reconciler packages.
-export type LanePriority =
-  | 0
-  | 1
-  | 2
-  | 3
-  | 4
-  | 5
-  | 6
-  | 7
-  | 8
-  | 9
-  | 10
-  | 11
-  | 12
-  | 13
-  | 14
-  | 15
-  | 16
-  | 17;
 
 export type Lanes = number;
 export type Lane = number;
@@ -44,28 +25,6 @@ import {
 import {isDevToolsPresent} from './ReactFiberDevToolsHook.old';
 import {ConcurrentUpdatesByDefaultMode, NoMode} from './ReactTypeOfMode';
 
-export const SyncLanePriority: LanePriority = 12;
-
-const InputContinuousHydrationLanePriority: LanePriority = 11;
-export const InputContinuousLanePriority: LanePriority = 10;
-
-const DefaultHydrationLanePriority: LanePriority = 9;
-export const DefaultLanePriority: LanePriority = 8;
-
-const TransitionHydrationPriority: LanePriority = 7;
-export const TransitionPriority: LanePriority = 6;
-
-const RetryLanePriority: LanePriority = 5;
-
-const SelectiveHydrationLanePriority: LanePriority = 4;
-
-const IdleHydrationLanePriority: LanePriority = 3;
-export const IdleLanePriority: LanePriority = 2;
-
-const OffscreenLanePriority: LanePriority = 1;
-
-export const NoLanePriority: LanePriority = 0;
-
 // Lane values below should be kept in sync with getLabelsForLanes(), used by react-devtools-scheduling-profiler.
 // If those values are changed that package should be rebuilt and redeployed.
 
@@ -169,29 +128,19 @@ export const NoTimestamp = -1;
 let nextTransitionLane: Lane = TransitionLane1;
 let nextRetryLane: Lane = RetryLane1;
 
-// "Registers" used to "return" multiple values
-// Used by getHighestPriorityLanes and getNextLanes:
-let return_highestLanePriority: LanePriority = DefaultLanePriority;
-
 function getHighestPriorityLanes(lanes: Lanes | Lane): Lanes {
   switch (getHighestPriorityLane(lanes)) {
     case SyncLane:
-      return_highestLanePriority = SyncLanePriority;
       return SyncLane;
     case InputContinuousHydrationLane:
-      return_highestLanePriority = InputContinuousHydrationLanePriority;
       return InputContinuousHydrationLane;
     case InputContinuousLane:
-      return_highestLanePriority = InputContinuousLanePriority;
       return InputContinuousLane;
     case DefaultHydrationLane:
-      return_highestLanePriority = DefaultHydrationLanePriority;
       return DefaultHydrationLane;
     case DefaultLane:
-      return_highestLanePriority = DefaultLanePriority;
       return DefaultLane;
     case TransitionHydrationLane:
-      return_highestLanePriority = TransitionHydrationPriority;
       return TransitionHydrationLane;
     case TransitionLane1:
     case TransitionLane2:
@@ -209,26 +158,20 @@ function getHighestPriorityLanes(lanes: Lanes | Lane): Lanes {
     case TransitionLane14:
     case TransitionLane15:
     case TransitionLane16:
-      return_highestLanePriority = TransitionPriority;
       return lanes & TransitionLanes;
     case RetryLane1:
     case RetryLane2:
     case RetryLane3:
     case RetryLane4:
     case RetryLane5:
-      return_highestLanePriority = RetryLanePriority;
       return lanes & RetryLanes;
     case SelectiveHydrationLane:
-      return_highestLanePriority = SelectiveHydrationLanePriority;
       return SelectiveHydrationLane;
     case IdleHydrationLane:
-      return_highestLanePriority = IdleHydrationLanePriority;
       return IdleHydrationLane;
     case IdleLane:
-      return_highestLanePriority = IdleLanePriority;
       return IdleLane;
     case OffscreenLane:
-      return_highestLanePriority = OffscreenLanePriority;
       return OffscreenLane;
     default:
       if (__DEV__) {
@@ -237,7 +180,6 @@ function getHighestPriorityLanes(lanes: Lanes | Lane): Lanes {
         );
       }
       // This shouldn't be reachable, but as a fallback, return the entire bitmask.
-      return_highestLanePriority = DefaultLanePriority;
       return lanes;
   }
 }
@@ -246,12 +188,10 @@ export function getNextLanes(root: FiberRoot, wipLanes: Lanes): Lanes {
   // Early bailout if there's no pending work left.
   const pendingLanes = root.pendingLanes;
   if (pendingLanes === NoLanes) {
-    return_highestLanePriority = NoLanePriority;
     return NoLanes;
   }
 
   let nextLanes = NoLanes;
-  let nextLanePriority = NoLanePriority;
 
   const suspendedLanes = root.suspendedLanes;
   const pingedLanes = root.pingedLanes;
@@ -263,12 +203,10 @@ export function getNextLanes(root: FiberRoot, wipLanes: Lanes): Lanes {
     const nonIdleUnblockedLanes = nonIdlePendingLanes & ~suspendedLanes;
     if (nonIdleUnblockedLanes !== NoLanes) {
       nextLanes = getHighestPriorityLanes(nonIdleUnblockedLanes);
-      nextLanePriority = return_highestLanePriority;
     } else {
       const nonIdlePingedLanes = nonIdlePendingLanes & pingedLanes;
       if (nonIdlePingedLanes !== NoLanes) {
         nextLanes = getHighestPriorityLanes(nonIdlePingedLanes);
-        nextLanePriority = return_highestLanePriority;
       }
     }
   } else {
@@ -276,11 +214,9 @@ export function getNextLanes(root: FiberRoot, wipLanes: Lanes): Lanes {
     const unblockedLanes = pendingLanes & ~suspendedLanes;
     if (unblockedLanes !== NoLanes) {
       nextLanes = getHighestPriorityLanes(unblockedLanes);
-      nextLanePriority = return_highestLanePriority;
     } else {
       if (pingedLanes !== NoLanes) {
         nextLanes = getHighestPriorityLanes(pingedLanes);
-        nextLanePriority = return_highestLanePriority;
       }
     }
   }
@@ -314,8 +250,6 @@ export function getNextLanes(root: FiberRoot, wipLanes: Lanes): Lanes {
     ) {
       // Keep working on the existing in-progress tree. Do not interrupt.
       return wipLanes;
-    } else {
-      return_highestLanePriority = nextLanePriority;
     }
   }
 
@@ -511,9 +445,6 @@ export function getLanesToRetrySynchronouslyOnError(root: FiberRoot): Lanes {
   return NoLanes;
 }
 
-export function returnNextLanesPriority() {
-  return return_highestLanePriority;
-}
 export function includesNonIdleWork(lanes: Lanes) {
   return (lanes & NonIdleLanes) !== NoLanes;
 }
@@ -623,13 +554,6 @@ export function higherPriorityLane(a: Lane, b: Lane) {
   return a !== NoLane && a < b ? a : b;
 }
 
-export function higherLanePriority(
-  a: LanePriority,
-  b: LanePriority,
-): LanePriority {
-  return a !== NoLanePriority && a > b ? a : b;
-}
-
 export function createLaneMap<T>(initial: T): LaneMap<T> {
   // Intentionally pushing one by one.
   // https://v8.dev/blog/elements-kinds#avoid-creating-holes