diff --git a/packages/effect-lens/src/Lens.ts b/packages/effect-lens/src/Lens.ts
index 3579b6a..5edc410 100644
--- a/packages/effect-lens/src/Lens.ts
+++ b/packages/effect-lens/src/Lens.ts
@@ -49,7 +49,7 @@ 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, EW | E1, RW | R1>
+    abstract readonly withLock: <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>) => Effect.Effect<A1, E1, R1>
 
     get get() { return Effect.map(this.resolve, frame => frame.value) }
 
@@ -82,7 +82,7 @@ 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, EW | E1, RW | R1>
+        readonly withLock: <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>) => Effect.Effect<A1, E1, R1>
     }
 }
 
@@ -129,7 +129,10 @@ export declare namespace DerivedLensImpl {
         in out RSW = never,
     > {
         readonly resolve: (effect: Effect.Effect<LensImpl.Frame<B, ESW, RSW>, ESR, RSR>) => Effect.Effect<LensImpl.Frame<A, EW, RW>, ER, RR>
-        readonly transformStream: (stream: Stream.Stream<B, ESR, RSR>) => Stream.Stream<A, 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>
     }
 }
 
@@ -154,8 +157,8 @@ extends LensImpl<A, ER, EW, RR, RW> {
     }
 
     get resolve() { return this.source.resolve(this.parent.resolve) }
-    get changes() { return this.source.transformStream(this.parent.changes) }
-    get withLock() { return this.parent.withLock }
+    get changes() { return this.source.mapStream(this.parent.changes) }
+    get withLock() { return this.source.withLock(this.parent.withLock) }
 }
 
 /**
@@ -322,25 +325,26 @@ export const map: {
     <A, ER, EW, RR, RW, B>(
         self: Lens<A, ER, EW, RR, RW>,
         get: (a: NoInfer<A>) => B,
-        update: (a: NoInfer<A>, b: B) => NoInfer<A>,
+        set: (a: NoInfer<A>, b: B) => NoInfer<A>,
     ): Lens<B, ER, EW, RR, RW>
     <A, ER, EW, RR, RW, B>(
         get: (a: NoInfer<A>) => B,
-        update: (a: NoInfer<A>, b: B) => NoInfer<A>,
+        set: (a: NoInfer<A>, b: B) => NoInfer<A>,
     ): (self: Lens<A, ER, EW, RR, RW>) => Lens<B, ER, EW, RR, RW>
 } = Function.dual(3, <A, ER, EW, RR, RW, B>(
     self: Lens<A, ER, EW, RR, RW>,
     get: (a: NoInfer<A>) => B,
-    update: (a: NoInfer<A>, b: B) => NoInfer<A>,
+    set: (a: NoInfer<A>, b: B) => NoInfer<A>,
 ): Lens<B, ER, EW, RR, RW> => derive(self, {
     resolve: parent => Effect.map(
         parent,
         frame => ({
             value: get(frame.value),
-            commit: next => frame.commit(Effect.map(next, b => update(frame.value, b))),
+            commit: next => frame.commit(Effect.map(next, b => set(frame.value, b))),
         }),
     ),
-    transformStream: Stream.map(get),
+    mapStream: Stream.map(get),
+    withLock: identity,
 }))
 
 /**
@@ -371,7 +375,8 @@ export const mapEffect: {
             }),
         ),
     ),
-    transformStream: Stream.mapEffect(get),
+    mapStream: Stream.mapEffect(get),
+    withLock: identity,
 }))
 
 /**
@@ -456,7 +461,8 @@ export const mapStream: {
     f: (changes: Stream.Stream<NoInfer<A>, NoInfer<ER>, NoInfer<RR>>) => Stream.Stream<NoInfer<A>, NoInfer<ER>, NoInfer<RR>>,
 ): Lens<A, ER, EW, RR, RW> => derive(self, {
     resolve: identity,
-    transformStream: f,
+    mapStream: f,
+    withLock: identity,
 }))
 
 
@@ -478,7 +484,8 @@ export const mapErrorRead: {
     f: (error: NoInfer<ER>) => E2,
 ): Lens<A, E2, EW, RR, RW> => derive(self, {
     resolve: Effect.mapError(f),
-    transformStream: Stream.mapError(f),
+    mapStream: Stream.mapError(f),
+    withLock: identity,
 }))
 
 /**
@@ -506,7 +513,8 @@ export const mapErrorWrite: {
             value => Effect.mapError(frame.commit(Effect.succeed(value)), f),
         ),
     })),
-    transformStream: identity,
+    mapStream: identity,
+    withLock: identity,
 }))
 
 /**
@@ -537,7 +545,8 @@ export const mapError: {
             ),
         }),
     ),
-    transformStream: Stream.mapError(f),
+    mapStream: Stream.mapError(f),
+    withLock: identity,
 }))
 
 /**
@@ -561,7 +570,8 @@ export const catchAllRead: {
         parent,
         error => asLensImpl(f(error)).resolve as Effect.Effect<LensImpl.Frame<A, EW | EW2, RW | RW2>, E2, R2>,
     ),
-    transformStream: Stream.catchAll(error => f(error).changes),
+    mapStream: Stream.catchAll(error => f(error).changes),
+    withLock: identity,
 } as DerivedLensImpl.Source<A, A, E2, ER, EW | EW2, EW, RR | R2, RR, RW | RW2, RW>))
 
 /**
@@ -588,7 +598,8 @@ export const catchAllWrite: {
             value => Effect.catchAll(frame.commit(Effect.succeed(value)), f),
         ),
     })),
-    transformStream: identity,
+    mapStream: identity,
+    withLock: identity,
 }))
 
 /**
@@ -609,7 +620,8 @@ export const tapErrorRead: {
     f: (error: NoInfer<ER>) => Effect.Effect<unknown, E2, R2>,
 ): Lens<A, ER | E2, EW, RR | R2, RW> => derive(self, {
     resolve: Effect.tapError(f),
-    transformStream: Stream.tapError(f),
+    mapStream: Stream.tapError(f),
+    withLock: identity,
 }))
 
 /**
@@ -637,7 +649,8 @@ export const tapErrorWrite: {
             value => Effect.tapError(frame.commit(Effect.succeed(value)), f),
         ),
     })),
-    transformStream: identity,
+    mapStream: identity,
+    withLock: identity,
 }))
 
 /**
@@ -668,7 +681,8 @@ export const tapError: {
             ),
         }),
     ),
-    transformStream: Stream.tapError(f),
+    mapStream: Stream.tapError(f),
+    withLock: identity,
 }))
 
 
@@ -694,7 +708,8 @@ export const provideContext: {
             commit: next => Effect.provide(frame.commit(Effect.provide(next, context)), context),
         }),
     ),
-    transformStream: Stream.provideSomeContext(context),
+    mapStream: Stream.provideSomeContext(context),
+    withLock: parentWithLock => self => Effect.provide(parentWithLock(Effect.provide(self, context)), context),
 }))
 
 /**
@@ -725,7 +740,8 @@ export const provideService: {
             commit: next => Effect.provideService(frame.commit(Effect.provideService(next, tag, service)), tag, service),
         }),
     ),
-    transformStream: Stream.provideService(tag, service),
+    mapStream: Stream.provideService(tag, service),
+    withLock: parentWithLock => self => Effect.provideService(parentWithLock(Effect.provideService(self, tag, service)), tag, service),
 }))