diff --git a/compiler/packages/babel-plugin-react-compiler/src/HIR/ObjectShape.ts b/compiler/packages/babel-plugin-react-compiler/src/HIR/ObjectShape.ts
index f396ae18b0461..f51768c586b72 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/ObjectShape.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/ObjectShape.ts
@@ -569,7 +569,7 @@ addObject(BUILTIN_SHAPES, BuiltInMixedReadonlyId, [
     'flatMap',
     addFunction(BUILTIN_SHAPES, [], {
       positionalParams: [],
-      restParam: Effect.Read,
+      restParam: Effect.ConditionallyMutate,
       returnType: {kind: 'Object', shapeId: BuiltInArrayId},
       calleeEffect: Effect.ConditionallyMutate,
       returnValueKind: ValueKind.Mutable,
@@ -580,7 +580,7 @@ addObject(BUILTIN_SHAPES, BuiltInMixedReadonlyId, [
     'filter',
     addFunction(BUILTIN_SHAPES, [], {
       positionalParams: [],
-      restParam: Effect.Read,
+      restParam: Effect.ConditionallyMutate,
       returnType: {kind: 'Object', shapeId: BuiltInArrayId},
       calleeEffect: Effect.ConditionallyMutate,
       returnValueKind: ValueKind.Mutable,
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-invalid-mixedreadonly-map-shape.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-invalid-mixedreadonly-map-shape.expect.md
deleted file mode 100644
index 1418062c33458..0000000000000
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-invalid-mixedreadonly-map-shape.expect.md
+++ /dev/null
@@ -1,163 +0,0 @@
-
-## Input
-
-```javascript
-import {
-  arrayPush,
-  identity,
-  makeArray,
-  Stringify,
-  useFragment,
-} from 'shared-runtime';
-
-/**
- * Bug repro showing why it's invalid for function references to be annotated
- * with a `Read` effect when that reference might lead to the function being
- * invoked.
- *
- * Note that currently, `Array.map` is annotated to have `Read` effects on its
- * operands. This is incorrect as function effects must be replayed when `map`
- * is called
- * - Read:                non-aliasing data dependency
- * - Capture:             maybe-aliasing data dependency
- * - ConditionallyMutate: maybe-aliasing data dependency; maybe-write / invoke
- *     but only if the value is mutable
- *
- * Invalid evaluator result: Found differences in evaluator results Non-forget
- * (expected): (kind: ok)
- *   <div>{"x":[2,2,2],"count":3}</div><div>{"item":1}</div>
- *   <div>{"x":[2,2,2],"count":4}</div><div>{"item":1}</div>
- * Forget:
- *   (kind: ok)
- *   <div>{"x":[2,2,2],"count":3}</div><div>{"item":1}</div>
- *   <div>{"x":[2,2,2,2,2,2],"count":4}</div><div>{"item":1}</div>
- */
-
-function Component({extraJsx}) {
-  const x = makeArray();
-  const items = useFragment();
-  const jsx = items.a.map((item, i) => {
-    arrayPush(x, 2);
-    return <Stringify item={item} key={i} />;
-  });
-  const offset = jsx.length;
-  for (let i = 0; i < extraJsx; i++) {
-    jsx.push(<Stringify item={0} key={i + offset} />);
-  }
-  const count = jsx.length;
-  identity(count);
-  return (
-    <>
-      <Stringify x={x} count={count} />
-      {jsx[0]}
-    </>
-  );
-}
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{extraJsx: 0}],
-  sequentialRenders: [{extraJsx: 0}, {extraJsx: 1}],
-};
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime";
-import {
-  arrayPush,
-  identity,
-  makeArray,
-  Stringify,
-  useFragment,
-} from "shared-runtime";
-
-/**
- * Bug repro showing why it's invalid for function references to be annotated
- * with a `Read` effect when that reference might lead to the function being
- * invoked.
- *
- * Note that currently, `Array.map` is annotated to have `Read` effects on its
- * operands. This is incorrect as function effects must be replayed when `map`
- * is called
- * - Read:                non-aliasing data dependency
- * - Capture:             maybe-aliasing data dependency
- * - ConditionallyMutate: maybe-aliasing data dependency; maybe-write / invoke
- *     but only if the value is mutable
- *
- * Invalid evaluator result: Found differences in evaluator results Non-forget
- * (expected): (kind: ok)
- *   <div>{"x":[2,2,2],"count":3}</div><div>{"item":1}</div>
- *   <div>{"x":[2,2,2],"count":4}</div><div>{"item":1}</div>
- * Forget:
- *   (kind: ok)
- *   <div>{"x":[2,2,2],"count":3}</div><div>{"item":1}</div>
- *   <div>{"x":[2,2,2,2,2,2],"count":4}</div><div>{"item":1}</div>
- */
-
-function Component(t0) {
-  const $ = _c(9);
-  const { extraJsx } = t0;
-  let t1;
-  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
-    t1 = makeArray();
-    $[0] = t1;
-  } else {
-    t1 = $[0];
-  }
-  const x = t1;
-  const items = useFragment();
-  let jsx;
-  if ($[1] !== extraJsx || $[2] !== items.a) {
-    jsx = items.a.map((item, i) => {
-      arrayPush(x, 2);
-      return <Stringify item={item} key={i} />;
-    });
-    const offset = jsx.length;
-    for (let i_0 = 0; i_0 < extraJsx; i_0++) {
-      jsx.push(<Stringify item={0} key={i_0 + offset} />);
-    }
-    $[1] = extraJsx;
-    $[2] = items.a;
-    $[3] = jsx;
-  } else {
-    jsx = $[3];
-  }
-
-  const count = jsx.length;
-  identity(count);
-  let t2;
-  if ($[4] !== count) {
-    t2 = <Stringify x={x} count={count} />;
-    $[4] = count;
-    $[5] = t2;
-  } else {
-    t2 = $[5];
-  }
-  const t3 = jsx[0];
-  let t4;
-  if ($[6] !== t2 || $[7] !== t3) {
-    t4 = (
-      <>
-        {t2}
-        {t3}
-      </>
-    );
-    $[6] = t2;
-    $[7] = t3;
-    $[8] = t4;
-  } else {
-    t4 = $[8];
-  }
-  return t4;
-}
-
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{ extraJsx: 0 }],
-  sequentialRenders: [{ extraJsx: 0 }, { extraJsx: 1 }],
-};
-
-```
-      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-invalid-mixedreadonly-map-shape.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-invalid-mixedreadonly-map-shape.js
deleted file mode 100644
index d038cf6cd38a1..0000000000000
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/bug-invalid-mixedreadonly-map-shape.js
+++ /dev/null
@@ -1,56 +0,0 @@
-import {
-  arrayPush,
-  identity,
-  makeArray,
-  Stringify,
-  useFragment,
-} from 'shared-runtime';
-
-/**
- * Bug repro showing why it's invalid for function references to be annotated
- * with a `Read` effect when that reference might lead to the function being
- * invoked.
- *
- * Note that currently, `Array.map` is annotated to have `Read` effects on its
- * operands. This is incorrect as function effects must be replayed when `map`
- * is called
- * - Read:                non-aliasing data dependency
- * - Capture:             maybe-aliasing data dependency
- * - ConditionallyMutate: maybe-aliasing data dependency; maybe-write / invoke
- *     but only if the value is mutable
- *
- * Invalid evaluator result: Found differences in evaluator results Non-forget
- * (expected): (kind: ok)
- *   <div>{"x":[2,2,2],"count":3}</div><div>{"item":1}</div>
- *   <div>{"x":[2,2,2],"count":4}</div><div>{"item":1}</div>
- * Forget:
- *   (kind: ok)
- *   <div>{"x":[2,2,2],"count":3}</div><div>{"item":1}</div>
- *   <div>{"x":[2,2,2,2,2,2],"count":4}</div><div>{"item":1}</div>
- */
-
-function Component({extraJsx}) {
-  const x = makeArray();
-  const items = useFragment();
-  const jsx = items.a.map((item, i) => {
-    arrayPush(x, 2);
-    return <Stringify item={item} key={i} />;
-  });
-  const offset = jsx.length;
-  for (let i = 0; i < extraJsx; i++) {
-    jsx.push(<Stringify item={0} key={i + offset} />);
-  }
-  const count = jsx.length;
-  identity(count);
-  return (
-    <>
-      <Stringify x={x} count={count} />
-      {jsx[0]}
-    </>
-  );
-}
-export const FIXTURE_ENTRYPOINT = {
-  fn: Component,
-  params: [{extraJsx: 0}],
-  sequentialRenders: [{extraJsx: 0}, {extraJsx: 1}],
-};