diff --git a/packages/babel-plugin-transform-typescript/src/index.ts b/packages/babel-plugin-transform-typescript/src/index.ts
index 3ce2557e4d..6daeb9fa26 100644
--- a/packages/babel-plugin-transform-typescript/src/index.ts
+++ b/packages/babel-plugin-transform-typescript/src/index.ts
@@ -291,7 +291,7 @@ export default declare((api, opts) => {
               }
             } else if (
               stmt.isTSTypeAliasDeclaration() ||
-              stmt.isTSDeclareFunction() ||
+              (stmt.isTSDeclareFunction() && stmt.get("id").isIdentifier()) ||
               stmt.isTSInterfaceDeclaration() ||
               stmt.isClassDeclaration({ declare: true }) ||
               stmt.isTSEnumDeclaration({ declare: true }) ||
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/exports/default-function/input.ts b/packages/babel-plugin-transform-typescript/test/fixtures/exports/default-function/input.ts
new file mode 100644
index 0000000000..0fd352cd26
--- /dev/null
+++ b/packages/babel-plugin-transform-typescript/test/fixtures/exports/default-function/input.ts
@@ -0,0 +1,3 @@
+export default function(choiceField: any, selectedIndex: number): void;
+export default function(choiceField: any, selectedValue: string): void;
+export default function(choiceField: any, selection: number | string) {}
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/exports/default-function/output.mjs b/packages/babel-plugin-transform-typescript/test/fixtures/exports/default-function/output.mjs
new file mode 100644
index 0000000000..fa096475e5
--- /dev/null
+++ b/packages/babel-plugin-transform-typescript/test/fixtures/exports/default-function/output.mjs
@@ -0,0 +1 @@
+export default function (choiceField, selection) {}