diff --git a/compiler/packages/babel-plugin-react-compiler/src/Inference/DropManualMemoization.ts b/compiler/packages/babel-plugin-react-compiler/src/Inference/DropManualMemoization.ts
index fdd9bcc968aef..4dcdc21e15ac5 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/Inference/DropManualMemoization.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Inference/DropManualMemoization.ts
@@ -488,7 +488,7 @@ export function dropManualMemoization(func: HIRFunction): void {
 function findOptionalPlaces(fn: HIRFunction): Set<IdentifierId> {
   const optionals = new Set<IdentifierId>();
   for (const [, block] of fn.body.blocks) {
-    if (block.terminal.kind === 'optional') {
+    if (block.terminal.kind === 'optional' && block.terminal.optional) {
       const optionalTerminal = block.terminal;
       let testBlock = fn.body.blocks.get(block.terminal.test)!;
       loop: while (true) {
diff --git a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidatePreservedManualMemoization.ts b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidatePreservedManualMemoization.ts
index 4f0c756585cf0..e7615320c7b95 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidatePreservedManualMemoization.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Validation/ValidatePreservedManualMemoization.ts
@@ -170,7 +170,7 @@ function compareDeps(
     if (inferred.path[i].property !== source.path[i].property) {
       isSubpath = false;
       break;
-    } else if (inferred.path[i].optional && !source.path[i].optional) {
+    } else if (inferred.path[i].optional !== source.path[i].optional) {
       /**
        * The inferred path must be at least as precise as the manual path:
        * if the inferred path is optional, then the source path must have
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-optional-member-expression-as-memo-dep-non-optional-in-body.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-optional-member-expression-as-memo-dep-non-optional-in-body.expect.md
new file mode 100644
index 0000000000000..ba5b30418069a
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-optional-member-expression-as-memo-dep-non-optional-in-body.expect.md
@@ -0,0 +1,38 @@
+
+## Input
+
+```javascript
+// @validatePreserveExistingMemoizationGuarantees
+function Component(props) {
+  const data = useMemo(() => {
+    // actual code is non-optional
+    return props.items.edges.nodes ?? [];
+    // deps are optional
+  }, [props.items?.edges?.nodes]);
+  return <Foo data={data} />;
+}
+
+```
+
+
+## Error
+
+```
+   1 | // @validatePreserveExistingMemoizationGuarantees
+   2 | function Component(props) {
+>  3 |   const data = useMemo(() => {
+     |                        ^^^^^^^
+>  4 |     // actual code is non-optional
+     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>  5 |     return props.items.edges.nodes ?? [];
+     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>  6 |     // deps are optional
+     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>  7 |   }, [props.items?.edges?.nodes]);
+     | ^^^^ CannotPreserveMemoization: React Compiler has skipped optimizing this component because the existing manual memoization could not be preserved. The inferred dependencies did not match the manually specified dependencies, which could cause the value to change more or less frequently than expected (3:7)
+   8 |   return <Foo data={data} />;
+   9 | }
+  10 |
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-as-memo-dep-non-optional-in-body.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-optional-member-expression-as-memo-dep-non-optional-in-body.js
similarity index 100%
rename from compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-as-memo-dep-non-optional-in-body.js
rename to compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-optional-member-expression-as-memo-dep-non-optional-in-body.js
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-as-memo-dep-non-optional-in-body.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-as-memo-dep-non-optional-in-body.expect.md
deleted file mode 100644
index 7cf1bcd90b339..0000000000000
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-as-memo-dep-non-optional-in-body.expect.md
+++ /dev/null
@@ -1,50 +0,0 @@
-
-## Input
-
-```javascript
-// @validatePreserveExistingMemoizationGuarantees
-function Component(props) {
-  const data = useMemo(() => {
-    // actual code is non-optional
-    return props.items.edges.nodes ?? [];
-    // deps are optional
-  }, [props.items?.edges?.nodes]);
-  return <Foo data={data} />;
-}
-
-```
-
-## Code
-
-```javascript
-import { c as _c } from "react/compiler-runtime"; // @validatePreserveExistingMemoizationGuarantees
-function Component(props) {
-  const $ = _c(4);
-
-  props.items?.edges?.nodes;
-  let t0;
-  let t1;
-  if ($[0] !== props.items.edges.nodes) {
-    t1 = props.items.edges.nodes ?? [];
-    $[0] = props.items.edges.nodes;
-    $[1] = t1;
-  } else {
-    t1 = $[1];
-  }
-  t0 = t1;
-  const data = t0;
-  let t2;
-  if ($[2] !== data) {
-    t2 = <Foo data={data} />;
-    $[2] = data;
-    $[3] = t2;
-  } else {
-    t2 = $[3];
-  }
-  return t2;
-}
-
-```
-      
-### Eval output
-(kind: exception) Fixture not implemented
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-single-with-unconditional.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-single-with-unconditional.expect.md
index d0c4afe459da2..46767056bdcdf 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-single-with-unconditional.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-single-with-unconditional.expect.md
@@ -10,8 +10,8 @@ function Component(props) {
     x.push(props?.items);
     x.push(props.items);
     return x;
-  }, [props?.items]);
-  return <ValidateMemoization inputs={[props?.items]} output={data} />;
+  }, [props.items]);
+  return <ValidateMemoization inputs={[props.items]} output={data} />;
 }
 
 ```
@@ -23,8 +23,6 @@ import { c as _c } from "react/compiler-runtime"; // @validatePreserveExistingMe
 import { ValidateMemoization } from "shared-runtime";
 function Component(props) {
   const $ = _c(7);
-
-  props?.items;
   let t0;
   let x;
   if ($[0] !== props.items) {
@@ -38,25 +36,24 @@ function Component(props) {
   }
   t0 = x;
   const data = t0;
-  const t1 = props?.items;
-  let t2;
-  if ($[2] !== t1) {
-    t2 = [t1];
-    $[2] = t1;
-    $[3] = t2;
+  let t1;
+  if ($[2] !== props.items) {
+    t1 = [props.items];
+    $[2] = props.items;
+    $[3] = t1;
   } else {
-    t2 = $[3];
+    t1 = $[3];
   }
-  let t3;
-  if ($[4] !== t2 || $[5] !== data) {
-    t3 = <ValidateMemoization inputs={t2} output={data} />;
-    $[4] = t2;
+  let t2;
+  if ($[4] !== t1 || $[5] !== data) {
+    t2 = <ValidateMemoization inputs={t1} output={data} />;
+    $[4] = t1;
     $[5] = data;
-    $[6] = t3;
+    $[6] = t2;
   } else {
-    t3 = $[6];
+    t2 = $[6];
   }
-  return t3;
+  return t2;
 }
 
 ```
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-single-with-unconditional.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-single-with-unconditional.js
index c630dd6bb4b9d..8e6275bf921eb 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-single-with-unconditional.js
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/optional-member-expression-single-with-unconditional.js
@@ -6,6 +6,6 @@ function Component(props) {
     x.push(props?.items);
     x.push(props.items);
     return x;
-  }, [props?.items]);
-  return <ValidateMemoization inputs={[props?.items]} output={data} />;
+  }, [props.items]);
+  return <ValidateMemoization inputs={[props.items]} output={data} />;
 }