diff --git a/tools/hermes-parser/js/flow-api-translator/__tests__/flowToFlowDef-test.js b/tools/hermes-parser/js/flow-api-translator/__tests__/flowToFlowDef-test.js
index afe7a89997d..9d25a6627a4 100644
--- a/tools/hermes-parser/js/flow-api-translator/__tests__/flowToFlowDef-test.js
+++ b/tools/hermes-parser/js/flow-api-translator/__tests__/flowToFlowDef-test.js
@@ -521,6 +521,12 @@ describe('flowToFlowDef', () => {
         `declare export class Foo<T> extends X {}`,
       );
     });
+    it('extends as cast expression', async () => {
+      await expectTranslate(
+        `export class Foo<T> extends (Bar as X) {}`,
+        `declare export class Foo<T> extends X {}`,
+      );
+    });
     it('extends type cast typeof expression', async () => {
       await expectTranslate(
         `export class Foo<T> extends (Bar: typeof X) {}`,
diff --git a/tools/hermes-parser/js/flow-api-translator/src/flowToFlowDef.js b/tools/hermes-parser/js/flow-api-translator/src/flowToFlowDef.js
index 6d7a05d9317..e2018329909 100644
--- a/tools/hermes-parser/js/flow-api-translator/src/flowToFlowDef.js
+++ b/tools/hermes-parser/js/flow-api-translator/src/flowToFlowDef.js
@@ -1047,8 +1047,12 @@ function convertSuperClass(
         context,
       );
     }
-    case 'TypeCastExpression': {
-      const typeAnnotation = superClass.typeAnnotation.typeAnnotation;
+    case 'TypeCastExpression':
+    case 'AsExpression': {
+      const typeAnnotation =
+        superClass.type === 'TypeCastExpression'
+          ? superClass.typeAnnotation.typeAnnotation
+          : superClass.typeAnnotation;
 
       if (typeAnnotation.type === 'GenericTypeAnnotation') {
         return convertSuperClassHelper(