diff --git a/packages/babel-generator/src/generators/typescript.ts b/packages/babel-generator/src/generators/typescript.ts
index cbb716f6ac4f..aae7f979d016 100644
--- a/packages/babel-generator/src/generators/typescript.ts
+++ b/packages/babel-generator/src/generators/typescript.ts
@@ -443,11 +443,12 @@ export function TSMappedType(this: Printer, node: t.TSMappedType) {
 
   this.token("]");
 
+  if (optional) {
+    tokenIfPlusMinus(this, optional);
+    this.token("?");
+  }
+
   if (typeAnnotation) {
-    if (optional) {
-      tokenIfPlusMinus(this, optional);
-      this.token("?");
-    }
     this.token(":");
     this.space();
     this.print(typeAnnotation, node);
diff --git a/packages/babel-generator/test/fixtures/typescript/mapped-type/input.ts b/packages/babel-generator/test/fixtures/typescript/mapped-type/input.ts
index 9c446e4ab103..611dd15d3377 100644
--- a/packages/babel-generator/test/fixtures/typescript/mapped-type/input.ts
+++ b/packages/babel-generator/test/fixtures/typescript/mapped-type/input.ts
@@ -1 +1,4 @@
 type Bar = { [key in Foo] };
+type Foo2 = { [key in Bar]? };
+type Foo3 = { [key in keyof Bar]-? };
+type Foo4 = { [key in keyof Bar]+? };
diff --git a/packages/babel-generator/test/fixtures/typescript/mapped-type/output.js b/packages/babel-generator/test/fixtures/typescript/mapped-type/output.js
index ebccaaab98fc..37b392920270 100644
--- a/packages/babel-generator/test/fixtures/typescript/mapped-type/output.js
+++ b/packages/babel-generator/test/fixtures/typescript/mapped-type/output.js
@@ -1 +1,4 @@
-type Bar = { [key in Foo] };
\ No newline at end of file
+type Bar = { [key in Foo] };
+type Foo2 = { [key in Bar]? };
+type Foo3 = { [key in keyof Bar]-? };
+type Foo4 = { [key in keyof Bar]+? };
\ No newline at end of file