diff --git a/compiler/forget/src/HIR/ObjectShape.ts b/compiler/forget/src/HIR/ObjectShape.ts
index f7bf3e3b29..43459357f0 100644
--- a/compiler/forget/src/HIR/ObjectShape.ts
+++ b/compiler/forget/src/HIR/ObjectShape.ts
@@ -159,7 +159,7 @@ addObject(BUILTIN_SHAPES, BuiltInArrayId, [
       positionalParams: [],
       restParam: Effect.Capture,
       returnType: PRIMITIVE_TYPE,
-      calleeEffect: Effect.Mutate,
+      calleeEffect: Effect.Store,
     }),
   ],
   // TODO: rest of Array properties
diff --git a/compiler/forget/src/Inference/InferAliasForStores.ts b/compiler/forget/src/Inference/InferAliasForStores.ts
index db8725dca1..11000e2a16 100644
--- a/compiler/forget/src/Inference/InferAliasForStores.ts
+++ b/compiler/forget/src/Inference/InferAliasForStores.ts
@@ -25,7 +25,15 @@ export function inferAliasForStores(
   for (const [_, block] of func.body.blocks) {
     for (const instr of block.instructions) {
       const { value, lvalue } = instr;
-      if (lvalue.effect !== Effect.Store) {
+      const isStore =
+        lvalue.effect === Effect.Store ||
+        // Some typed functions annotate callees or arguments
+        // as Effect.Store.
+        ![...eachInstructionValueOperand(value)].every(
+          (operand) => operand.effect !== Effect.Store
+        );
+
+      if (!isStore) {
         continue;
       }
       for (const operand of eachInstructionLValue(instr)) {
diff --git a/compiler/forget/src/Inference/InferReferenceEffects.ts b/compiler/forget/src/Inference/InferReferenceEffects.ts
index 9704e67e9e..cce90565d9 100644
--- a/compiler/forget/src/Inference/InferReferenceEffects.ts
+++ b/compiler/forget/src/Inference/InferReferenceEffects.ts
@@ -323,6 +323,20 @@ class InferenceState {
         break;
       }
       case Effect.Store: {
+        if (
+          valueKind !== ValueKind.Mutable &&
+          valueKind !== ValueKind.Context &&
+          shouldError
+        ) {
+          CompilerError.invalidInput(
+            `InferReferenceEffects: inferred mutation of known immutable value`,
+            place.loc,
+            `Found mutation of ${printIdentifier(place.identifier)}${printType(
+              place.identifier.type
+            )} (${valueKind})`
+          );
+        }
+
         // TODO(gsn): This should be bailout once we add bailout infra.
         //
         // invariant(
diff --git a/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver-and-mutate.expect.md b/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver-and-mutate.expect.md
new file mode 100644
index 0000000000..c405f36edb
--- /dev/null
+++ b/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver-and-mutate.expect.md
@@ -0,0 +1,51 @@
+
+## Input
+
+```javascript
+function Component() {
+  // a's mutable range should be the same as x's mutable range,
+  // since a is captured into x (which gets mutated later)
+  let a = someObj();
+
+  let x = [];
+  x.push(a);
+
+  mutate(x);
+  return [x, a];
+}
+
+```
+
+## Code
+
+```javascript
+import { unstable_useMemoCache as useMemoCache } from "react";
+function Component() {
+  const $ = useMemoCache(3);
+  let x;
+  let a;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    a = someObj();
+
+    x = [];
+    x.push(a);
+
+    mutate(x);
+    $[0] = x;
+    $[1] = a;
+  } else {
+    x = $[0];
+    a = $[1];
+  }
+  let t0;
+  if ($[2] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = [x, a];
+    $[2] = t0;
+  } else {
+    t0 = $[2];
+  }
+  return t0;
+}
+
+```
+      
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver-and-mutate.js b/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver-and-mutate.js
new file mode 100644
index 0000000000..13470813eb
--- /dev/null
+++ b/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver-and-mutate.js
@@ -0,0 +1,11 @@
+function Component() {
+  // a's mutable range should be the same as x's mutable range,
+  // since a is captured into x (which gets mutated later)
+  let a = someObj();
+
+  let x = [];
+  x.push(a);
+
+  mutate(x);
+  return [x, a];
+}
diff --git a/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver.expect.md b/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver.expect.md
new file mode 100644
index 0000000000..96bc86b771
--- /dev/null
+++ b/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver.expect.md
@@ -0,0 +1,51 @@
+
+## Input
+
+```javascript
+function Component() {
+  // a's mutable range should be limited
+  // the following line
+  let a = someObj();
+
+  let x = [];
+  x.push(a);
+
+  return [x, a];
+}
+
+```
+
+## Code
+
+```javascript
+import { unstable_useMemoCache as useMemoCache } from "react";
+function Component() {
+  const $ = useMemoCache(3);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = someObj();
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  const a = t0;
+  let x;
+  if ($[1] === Symbol.for("react.memo_cache_sentinel")) {
+    x = [];
+    x.push(a);
+    $[1] = x;
+  } else {
+    x = $[1];
+  }
+  let t1;
+  if ($[2] === Symbol.for("react.memo_cache_sentinel")) {
+    t1 = [x, a];
+    $[2] = t1;
+  } else {
+    t1 = $[2];
+  }
+  return t1;
+}
+
+```
+      
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver.js b/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver.js
new file mode 100644
index 0000000000..9b2dbbdd1b
--- /dev/null
+++ b/compiler/forget/src/__tests__/fixtures/compiler/alias-capture-in-method-receiver.js
@@ -0,0 +1,10 @@
+function Component() {
+  // a's mutable range should be limited
+  // the following line
+  let a = someObj();
+
+  let x = [];
+  x.push(a);
+
+  return [x, a];
+}