diff --git a/packages/effect-lens/src/Lens.test.ts b/packages/effect-lens/src/Lens.test.ts
index de10c5d..9a62dce 100644
--- a/packages/effect-lens/src/Lens.test.ts
+++ b/packages/effect-lens/src/Lens.test.ts
@@ -12,7 +12,7 @@ describe("Lens", () => {
                 get: Effect.fail("read" as const),
                 changes: Stream.fail("read" as const),
                 commit: () => Effect.void,
-                withLock: identity,
+                lock: Effect.succeed(identity),
             }),
             error => `mapped:${ error }`,
         )
@@ -28,7 +28,7 @@ describe("Lens", () => {
                 get: Effect.succeed(1),
                 changes: Stream.make(1),
                 commit: () => Effect.fail("write" as const),
-                withLock: identity,
+                lock: Effect.succeed(identity),
             }),
             () => "mapped-write",
         )
@@ -44,7 +44,7 @@ describe("Lens", () => {
                 get: Effect.fail("read" as const),
                 changes: Stream.fail("read" as const),
                 commit: () => Effect.fail("write" as const),
-                withLock: identity,
+                lock: Effect.succeed(identity),
             }),
             () => "mapped",
         )
@@ -68,7 +68,7 @@ describe("Lens", () => {
                             get: Effect.fail("read" as const),
                             changes: Stream.fail("read" as const),
                             commit: () => Effect.void,
-                            withLock: identity,
+                            lock: Effect.succeed(identity),
                         }),
                         () => Lens.fromSubscriptionRef(fallback),
                     ),
@@ -89,7 +89,7 @@ describe("Lens", () => {
                             get: Effect.fail("read" as const),
                             changes: Stream.fail("read" as const),
                             commit: () => Effect.void,
-                            withLock: identity,
+                            lock: Effect.succeed(identity),
                         }),
                         () => SubscriptionRef.modify(counter, n => [void 0, n + 1] as const),
                     )
@@ -114,7 +114,7 @@ describe("Lens", () => {
                             get: Effect.succeed(1),
                             changes: Stream.make(1),
                             commit: () => Effect.fail("write" as const),
-                            withLock: identity,
+                            lock: Effect.succeed(identity),
                         }),
                         () => SubscriptionRef.modify(counter, n => [void 0, n + 1] as const),
                     )
diff --git a/packages/effect-lens/src/Lens.ts b/packages/effect-lens/src/Lens.ts
index 5edc410..c581347 100644
--- a/packages/effect-lens/src/Lens.ts
+++ b/packages/effect-lens/src/Lens.ts
@@ -38,6 +38,10 @@ export declare namespace LensImpl {
             next: Effect.Effect<A, E, R>
         ) => Effect.Effect<void, EW | E, RW | R>
     }
+
+    export interface Lock {
+        <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>): Effect.Effect<A1, E1, R1>
+    }
 }
 
 export abstract class LensImpl<in out A, in out ER = never, in out EW = never, in out RR = never, in out RW = never>
@@ -49,20 +53,23 @@ extends Pipeable.Class() implements Lens<A, ER, EW, RR, RW> {
 
     abstract readonly resolve: Effect.Effect<LensImpl.Frame<A, EW, RW>, ER, RR>
     abstract readonly changes: Stream.Stream<A, ER, RR>
-    abstract readonly withLock: <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>) => Effect.Effect<A1, E1, R1>
+    abstract readonly lock: Effect.Effect<LensImpl.Lock, EW, RW>
 
     get get() { return Effect.map(this.resolve, frame => frame.value) }
 
     modifyEffect<B, E1 = never, R1 = never>(
         f: (a: A) => Effect.Effect<readonly [B, A], E1, R1>,
     ): Effect.Effect<B, ER | EW | E1, RR | RW | R1> {
-        return this.withLock(Effect.flatMap(
-            this.resolve,
-            frame => Effect.flatMap(
-                f(frame.value),
-                ([c, next]) => Effect.as(frame.commit(Effect.succeed(next)), c),
-            ),
-        ))
+        return Effect.flatMap(
+            this.lock,
+            lock => lock(Effect.flatMap(
+                this.resolve,
+                frame => Effect.flatMap(
+                    f(frame.value),
+                    ([c, next]) => Effect.as(frame.commit(Effect.succeed(next)), c),
+                ),
+            )),
+        )
     }
 }
 
@@ -82,7 +89,7 @@ export declare namespace LensLazyImpl {
         readonly get: Effect.Effect<A, ER, RR>
         readonly changes: Stream.Stream<A, ER, RR>
         readonly commit: (a: A) => Effect.Effect<void, EW, RW>
-        readonly withLock: <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>) => Effect.Effect<A1, E1, R1>
+        readonly lock: Effect.Effect<LensImpl.Lock, EW, RW>
     }
 }
 
@@ -104,7 +111,7 @@ extends LensImpl<A, ER, EW, RR, RW> {
         )
     }
     get changes() { return this.source.changes }
-    get withLock() { return this.source.withLock }
+    get lock() { return this.source.lock }
 }
 
 /**
@@ -130,9 +137,7 @@ export declare namespace DerivedLensImpl {
     > {
         readonly resolve: (effect: Effect.Effect<LensImpl.Frame<B, ESW, RSW>, ESR, RSR>) => Effect.Effect<LensImpl.Frame<A, EW, RW>, ER, RR>
         readonly mapStream: (stream: Stream.Stream<B, ESR, RSR>) => Stream.Stream<A, ER, RR>
-        readonly withLock: (
-            withLock: <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>) => Effect.Effect<A1, E1, R1>
-        ) => <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>) => Effect.Effect<A1, E1, R1>
+        readonly mapLock: (lock: Effect.Effect<LensImpl.Lock, ESW, RSW>) => Effect.Effect<LensImpl.Lock, EW, RW>
     }
 }
 
@@ -158,7 +163,7 @@ extends LensImpl<A, ER, EW, RR, RW> {
 
     get resolve() { return this.source.resolve(this.parent.resolve) }
     get changes() { return this.source.mapStream(this.parent.changes) }
-    get withLock() { return this.source.withLock(this.parent.withLock) }
+    get lock() { return this.source.mapLock(this.parent.lock) }
 }
 
 /**
@@ -200,7 +205,7 @@ extends LensImpl<A, never, never, never, never> {
         )
     }
     get changes() { return Stream.unwrap(Effect.map(Ref.get(this.ref), Stream.make)) }
-    get withLock() { return this.semaphore.withPermits(1) }
+    get lock() { return Effect.succeed(this.semaphore.withPermits(1)) }
 }
 
 /**
@@ -220,7 +225,7 @@ export declare namespace SynchronizedRefLensImpl {
     export interface SynchronizedRefWithInternals<in out A>
     extends SynchronizedRef.SynchronizedRef<A> {
         readonly ref: Ref.Ref<A>
-        readonly withLock: <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>) => Effect.Effect<A1, E1, R1>
+        readonly withLock: LensImpl.Lock
     }
 }
 
@@ -245,7 +250,7 @@ extends LensImpl<A, never, never, never, never> {
         )
     }
     get changes() { return Stream.unwrap(Effect.map(Ref.get(this.ref.ref), Stream.make)) }
-    get withLock() { return this.ref.withLock }
+    get lock() { return Effect.succeed(this.ref.withLock) }
 }
 
 /**
@@ -292,7 +297,7 @@ extends LensImpl<A, never, never, never, never> {
         )
     }
     get changes() { return this.ref.changes }
-    get withLock() { return this.ref.semaphore.withPermits(1) }
+    get lock() { return Effect.succeed(this.ref.semaphore.withPermits(1)) }
 }
 
 /**
@@ -315,7 +320,7 @@ export const unwrap = <A, ER, EW, RR, RW, E1, R1>(
         effect,
         l => Effect.flatMap(asLensImpl(l).resolve, frame => frame.commit(Effect.succeed(a))),
     ),
-    withLock: <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>) => Effect.flatMap(effect, l => asLensImpl(l).withLock(self)),
+    lock: Effect.flatMap(effect, l => asLensImpl(l).lock),
 })
 
 /**
@@ -344,7 +349,7 @@ export const map: {
         }),
     ),
     mapStream: Stream.map(get),
-    withLock: identity,
+    mapLock: identity,
 }))
 
 /**
@@ -376,7 +381,7 @@ export const mapEffect: {
         ),
     ),
     mapStream: Stream.mapEffect(get),
-    withLock: identity,
+    mapLock: lock => lock as Effect.Effect<LensImpl.Lock, EW | ESet, RW | RSet>,
 }))
 
 /**
@@ -462,7 +467,7 @@ export const mapStream: {
 ): Lens<A, ER, EW, RR, RW> => derive(self, {
     resolve: identity,
     mapStream: f,
-    withLock: identity,
+    mapLock: identity,
 }))
 
 
@@ -485,7 +490,7 @@ export const mapErrorRead: {
 ): Lens<A, E2, EW, RR, RW> => derive(self, {
     resolve: Effect.mapError(f),
     mapStream: Stream.mapError(f),
-    withLock: identity,
+    mapLock: identity,
 }))
 
 /**
@@ -514,7 +519,7 @@ export const mapErrorWrite: {
         ),
     })),
     mapStream: identity,
-    withLock: identity,
+    mapLock: Effect.mapError(f),
 }))
 
 /**
@@ -546,7 +551,7 @@ export const mapError: {
         }),
     ),
     mapStream: Stream.mapError(f),
-    withLock: identity,
+    mapLock: Effect.mapError(f),
 }))
 
 /**
@@ -571,7 +576,7 @@ export const catchAllRead: {
         error => asLensImpl(f(error)).resolve as Effect.Effect<LensImpl.Frame<A, EW | EW2, RW | RW2>, E2, R2>,
     ),
     mapStream: Stream.catchAll(error => f(error).changes),
-    withLock: identity,
+    mapLock: lock => lock as Effect.Effect<LensImpl.Lock, EW | EW2, RW | RW2>,
 } as DerivedLensImpl.Source<A, A, E2, ER, EW | EW2, EW, RR | R2, RR, RW | RW2, RW>))
 
 /**
@@ -599,7 +604,10 @@ export const catchAllWrite: {
         ),
     })),
     mapStream: identity,
-    withLock: identity,
+    mapLock: lock => Effect.catchAll(
+        lock,
+        error => Effect.as(f(error), identityLock),
+    ),
 }))
 
 /**
@@ -621,7 +629,7 @@ export const tapErrorRead: {
 ): Lens<A, ER | E2, EW, RR | R2, RW> => derive(self, {
     resolve: Effect.tapError(f),
     mapStream: Stream.tapError(f),
-    withLock: identity,
+    mapLock: lock => lock,
 }))
 
 /**
@@ -650,7 +658,7 @@ export const tapErrorWrite: {
         ),
     })),
     mapStream: identity,
-    withLock: identity,
+    mapLock: lock => Effect.tapError(lock, f),
 }))
 
 /**
@@ -682,7 +690,7 @@ export const tapError: {
         }),
     ),
     mapStream: Stream.tapError(f),
-    withLock: identity,
+    mapLock: lock => Effect.tapError(lock, f),
 }))
 
 
@@ -709,7 +717,10 @@ export const provideContext: {
         }),
     ),
     mapStream: Stream.provideSomeContext(context),
-    withLock: parentWithLock => self => Effect.provide(parentWithLock(Effect.provide(self, context)), context),
+    mapLock: lock => Effect.map(
+        Effect.provide(lock, context),
+        lock => self => Effect.provide(lock(Effect.provide(self, context)), context),
+    ),
 }))
 
 /**
@@ -741,7 +752,10 @@ export const provideService: {
         }),
     ),
     mapStream: Stream.provideService(tag, service),
-    withLock: parentWithLock => self => Effect.provideService(parentWithLock(Effect.provideService(self, tag, service)), tag, service),
+    mapLock: lock => Effect.map(
+        Effect.provideService(lock, tag, service),
+        lock => self => Effect.provideService(lock(Effect.provideService(self, tag, service)), tag, service),
+    ),
 }))
 
 
diff --git a/packages/effect-lens/src/tests.ts b/packages/effect-lens/src/tests.ts
index 09d16b7..6cb06f5 100644
--- a/packages/effect-lens/src/tests.ts
+++ b/packages/effect-lens/src/tests.ts
@@ -33,7 +33,7 @@ Effect.gen(function*() {
             get: Effect.succeed("User not found"),
             changes: Stream.make("User not found"),
             commit: () => Console.log("Test"),
-            withLock: Effect.unsafeMakeSemaphore(1).withPermits(1),
+            lock: Effect.succeed(Effect.unsafeMakeSemaphore(1).withPermits(1)),
         })),
     )