diff --git a/packages/effect-lens/src/Lens.ts b/packages/effect-lens/src/Lens.ts
index d9c1910..0016c73 100644
--- a/packages/effect-lens/src/Lens.ts
+++ b/packages/effect-lens/src/Lens.ts
@@ -35,21 +35,21 @@ export interface LensStep<
     in out A,
     in out B,
     in out ER = never,
+    in out ESR = never,
     in out EW = never,
+    in out ESW = never,
     in out RR = never,
+    in out RSR = never,
     in out RW = never,
-    in out SourceER = never,
-    in out SourceEW = never,
-    in out SourceRR = never,
-    in out SourceRW = never,
+    in out RSW = never,
 > {
     readonly [LensStepTypeId]: LensStepTypeId
-    readonly transform: (effect: Effect.Effect<B, SourceER, SourceRR>) => Effect.Effect<A, ER, RR>
-    readonly transformStream: (stream: Stream.Stream<B, SourceER, SourceRR>) => Stream.Stream<A, ER, RR>
-    readonly update: (next: Effect.Effect<A, SourceEW, SourceRW>, parent: B) => Effect.Effect<B, EW, RW>
+    readonly transform: (effect: Effect.Effect<B, ESR, RSR>) => Effect.Effect<A, ER, RR>
+    readonly transformStream: (stream: Stream.Stream<B, ESR, RSR>) => Stream.Stream<A, ER, RR>
+    readonly update: (next: Effect.Effect<A, ESW, RSW>, parent: B) => Effect.Effect<B, EW, RW>
 }
 
-export const isLensStep = (u: unknown): u is LensStep<unknown, unknown, unknown, unknown, unknown, unknown> => Predicate.hasProperty(u, LensStepTypeId)
+export const isLensStep = (u: unknown): u is LensStep<unknown, unknown, unknown, unknown, unknown, unknown, unknown, unknown, unknown, unknown> => Predicate.hasProperty(u, LensStepTypeId)
 
 
 // export const asLensWithInternals = <A, ER, EW, RR, RW>(
@@ -68,13 +68,13 @@ export abstract class LensImpl<
     in out A,
     in out B,
     in out ER = never,
+    in out ESR = never,
     in out EW = never,
+    in out ESW = never,
     in out RR = never,
+    in out RSR = never,
     in out RW = never,
-    in out SourceER = never,
-    in out SourceEW = never,
-    in out SourceRR = never,
-    in out SourceRW = never,
+    in out RSW = never,
 >
 extends Pipeable.Class() implements Lens<A, ER, EW, RR, RW> {
     readonly [Readable.TypeId]: Readable.TypeId = Readable.TypeId
@@ -84,9 +84,9 @@ extends Pipeable.Class() implements Lens<A, ER, EW, RR, RW> {
 
     readonly steps: readonly LensStep<unknown, unknown, unknown, unknown, unknown, unknown, unknown, unknown, unknown, unknown>[] = []
 
-    abstract readonly sourceGet: Effect.Effect<B, SourceER, SourceRR>
-    abstract readonly sourceChanges: Stream.Stream<B, SourceER, SourceRR>
-    abstract readonly sourceCommit: (b: B) => Effect.Effect<void, SourceEW, SourceRW>
+    abstract readonly sourceGet: Effect.Effect<B, ESR, RSR>
+    abstract readonly sourceChanges: Stream.Stream<B, ESR, RSR>
+    abstract readonly sourceCommit: (b: B) => Effect.Effect<void, ESW, RSW>
     abstract readonly withLock: <A1, E1, R1>(self: Effect.Effect<A1, E1, R1>) => Effect.Effect<A1, EW | E1, RW | R1>
 
     get get(): Effect.Effect<A, ER, RR> {