diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-annotation_.flow.expect.md b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-annotation_.flow.expect.md
new file mode 100644
index 0000000000..0f9f6287d2
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-annotation_.flow.expect.md
@@ -0,0 +1,30 @@
+
+## Input
+
+```javascript
+// @flow @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsAnnotation() {
+  type Foo = Bar;
+  const fun = (f: Foo) => {
+    console.log(f);
+  };
+  fun("hello, world");
+}
+
+```
+
+
+## Error
+
+```
+  3 | function TypeAliasUsedAsAnnotation() {
+  4 |   type Foo = Bar;
+> 5 |   const fun = (f: Foo) => {
+    |                   ^^^ [ReactForget] Invariant: [hoisting] Expected value for identifier to be initialized. Foo$0 (5:5)
+  6 |     console.log(f);
+  7 |   };
+  8 |   fun("hello, world");
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-annotation_.flow.js b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-annotation_.flow.js
new file mode 100644
index 0000000000..748635b321
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-annotation_.flow.js
@@ -0,0 +1,9 @@
+// @flow @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsAnnotation() {
+  type Foo = Bar;
+  const fun = (f: Foo) => {
+    console.log(f);
+  };
+  fun("hello, world");
+}
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-variable-annotation_.flow.expect.md b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-variable-annotation_.flow.expect.md
new file mode 100644
index 0000000000..ab781e8db9
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-variable-annotation_.flow.expect.md
@@ -0,0 +1,31 @@
+
+## Input
+
+```javascript
+// @flow @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsAnnotation() {
+  type Foo = Bar;
+  const fun = (f) => {
+    let g: Foo = f;
+    console.log(g);
+  };
+  fun("hello, world");
+}
+
+```
+
+
+## Error
+
+```
+  4 |   type Foo = Bar;
+  5 |   const fun = (f) => {
+> 6 |     let g: Foo = f;
+    |            ^^^ [ReactForget] Invariant: [hoisting] Expected value for identifier to be initialized. Foo$0 (6:6)
+  7 |     console.log(g);
+  8 |   };
+  9 |   fun("hello, world");
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-variable-annotation_.flow.js b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-variable-annotation_.flow.js
new file mode 100644
index 0000000000..64966640a9
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.type-alias-used-as-variable-annotation_.flow.js
@@ -0,0 +1,10 @@
+// @flow @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsAnnotation() {
+  type Foo = Bar;
+  const fun = (f) => {
+    let g: Foo = f;
+    console.log(g);
+  };
+  fun("hello, world");
+}
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-annotation.expect.md b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-annotation.expect.md
new file mode 100644
index 0000000000..02a31ec938
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-annotation.expect.md
@@ -0,0 +1,44 @@
+
+## Input
+
+```javascript
+// @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsParamAnnotation() {
+  type Foo = Bar;
+  const fun = (f: Foo) => {
+    console.log(f);
+  };
+  fun("hello, world");
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: TypeAliasUsedAsParamAnnotation,
+  params: [],
+};
+
+```
+
+## Code
+
+```javascript
+// @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsParamAnnotation() {
+  const fun = (f) => {
+    console.log(f);
+  };
+
+  fun("hello, world");
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: TypeAliasUsedAsParamAnnotation,
+  params: [],
+};
+
+```
+      
+### Eval output
+(kind: ok) 
+logs: ['hello, world']
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-annotation.ts b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-annotation.ts
new file mode 100644
index 0000000000..d8eb6093d5
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-annotation.ts
@@ -0,0 +1,14 @@
+// @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsParamAnnotation() {
+  type Foo = Bar;
+  const fun = (f: Foo) => {
+    console.log(f);
+  };
+  fun("hello, world");
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: TypeAliasUsedAsParamAnnotation,
+  params: [],
+};
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-variable-annotation.expect.md b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-variable-annotation.expect.md
new file mode 100644
index 0000000000..f97bcbb3a6
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-variable-annotation.expect.md
@@ -0,0 +1,46 @@
+
+## Input
+
+```javascript
+// @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsVariableAnnotation() {
+  type Foo = Bar;
+  const fun = (f) => {
+    let g: Foo = f;
+    console.log(g);
+  };
+  fun("hello, world");
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: TypeAliasUsedAsVariableAnnotation,
+  params: [],
+};
+
+```
+
+## Code
+
+```javascript
+// @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsVariableAnnotation() {
+  const fun = (f) => {
+    const g = f;
+    console.log(g);
+  };
+
+  fun("hello, world");
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: TypeAliasUsedAsVariableAnnotation,
+  params: [],
+};
+
+```
+      
+### Eval output
+(kind: ok) 
+logs: ['hello, world']
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-variable-annotation.ts b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-variable-annotation.ts
new file mode 100644
index 0000000000..8b8b0bfb41
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/type-alias-used-as-variable-annotation.ts
@@ -0,0 +1,15 @@
+// @enableAssumeHooksFollowRulesOfReact @enableTransitivelyFreezeFunctionExpressions
+type Bar = string;
+function TypeAliasUsedAsVariableAnnotation() {
+  type Foo = Bar;
+  const fun = (f) => {
+    let g: Foo = f;
+    console.log(g);
+  };
+  fun("hello, world");
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: TypeAliasUsedAsVariableAnnotation,
+  params: [],
+};