diff --git a/packages/babel-generator/src/generators/flow.js b/packages/babel-generator/src/generators/flow.js
index cceef1c9f0..15f39923ca 100644
--- a/packages/babel-generator/src/generators/flow.js
+++ b/packages/babel-generator/src/generators/flow.js
@@ -199,6 +199,13 @@ export function TypeParameter(node: Object) {
   if (node.bound) {
     this.print(node.bound, node);
   }
+
+  if (node.default) {
+    this.space();
+    this.push("=");
+    this.space();
+    this.print(node.default, node);
+  }
 }
 
 export function TypeParameterInstantiation(node: Object) {
diff --git a/packages/babel-generator/test/fixtures/flow/type-parameters/actual.js b/packages/babel-generator/test/fixtures/flow/type-parameters/actual.js
new file mode 100644
index 0000000000..8c307485e8
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/flow/type-parameters/actual.js
@@ -0,0 +1,21 @@
+type A<T = string> = T;
+type A<T = *> = T;
+type A<T: ?string = string> = T;
+type A<S, T: ?string = string> = T;
+type A<S = number, T: ?string = string> = T;
+class A<T = string> {};
+class A<T: ?string = string> {};
+class A<S, T: ?string = string> {};
+class A<S = number, T: ?string = string> {};
+(class A<T = string> {});
+(class A<T: ?string = string> {});
+(class A<S, T: ?string = string> {});
+(class A<S = number, T: ?string = string> {});
+declare class A<T = string> {};
+declare class A<T: ?string = string> {};
+declare class A<S, T: ?string = string> {};
+declare class A<S = number, T: ?string = string> {};
+interface A<T = string> {};
+interface A<T: ?string = string> {};
+interface A<S, T: ?string = string> {};
+interface A<S = number, T: ?string = string> {};
diff --git a/packages/babel-generator/test/fixtures/flow/type-parameters/expected.js b/packages/babel-generator/test/fixtures/flow/type-parameters/expected.js
new file mode 100644
index 0000000000..8c307485e8
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/flow/type-parameters/expected.js
@@ -0,0 +1,21 @@
+type A<T = string> = T;
+type A<T = *> = T;
+type A<T: ?string = string> = T;
+type A<S, T: ?string = string> = T;
+type A<S = number, T: ?string = string> = T;
+class A<T = string> {};
+class A<T: ?string = string> {};
+class A<S, T: ?string = string> {};
+class A<S = number, T: ?string = string> {};
+(class A<T = string> {});
+(class A<T: ?string = string> {});
+(class A<S, T: ?string = string> {});
+(class A<S = number, T: ?string = string> {});
+declare class A<T = string> {};
+declare class A<T: ?string = string> {};
+declare class A<S, T: ?string = string> {};
+declare class A<S = number, T: ?string = string> {};
+interface A<T = string> {};
+interface A<T: ?string = string> {};
+interface A<S, T: ?string = string> {};
+interface A<S = number, T: ?string = string> {};