diff --git a/packages/babel-plugin-minify-mangle-names/__tests__/mangle-names-test.js b/packages/babel-plugin-minify-mangle-names/__tests__/mangle-names-test.js
index dba6acc27..b31ba48ff 100644
--- a/packages/babel-plugin-minify-mangle-names/__tests__/mangle-names-test.js
+++ b/packages/babel-plugin-minify-mangle-names/__tests__/mangle-names-test.js
@@ -4,9 +4,9 @@ const traverse = require("babel-traverse").default;
 const babel    = require("babel-core");
 const unpad    = require("../../../utils/unpad");
 
-function transform(code, options = {}) {
+function transform(code, options = {}, sourceType = "script") {
   return babel.transform(code,  {
-    sourceType: "script",
+    sourceType,
     plugins: [
       [require("../src/index"), options],
     ],
@@ -873,4 +873,34 @@ describe("mangle-names", () => {
     `);
     expect(transform(source)).toBe(expected);
   });
+
+  it("should handle export declarations", () => {
+    const source = unpad(`
+      const foo = 1;
+      export { foo };
+      export const bar = 2;
+      export function baz(bar, foo) {
+        bar();
+        foo();
+      };
+      export default function (bar, baz) {
+        bar();
+        baz();
+      }
+    `);
+    const expected = unpad(`
+      const foo = 1;
+      export { foo };
+      export const bar = 2;
+      export function baz(a, b) {
+        a();
+        b();
+      };
+      export default function (a, b) {
+        a();
+        b();
+      }
+    `);
+    expect(transform(source, {}, "module")).toBe(expected);
+  });
 });
diff --git a/packages/babel-plugin-minify-mangle-names/src/index.js b/packages/babel-plugin-minify-mangle-names/src/index.js
index e045130cf..c7fa5638f 100644
--- a/packages/babel-plugin-minify-mangle-names/src/index.js
+++ b/packages/babel-plugin-minify-mangle-names/src/index.js
@@ -163,11 +163,22 @@ module.exports = ({ types: t }) => {
         const path = refs[i];
         const {node} = path;
         if (!path.isIdentifier()) {
-          // if this occurs, then it is
-          // probably an upstream bug (in babel)
-          throw new Error("Unexpected " + path.node.type + ". Expected an Identifier");
-        }
-        if (!isLabelIdentifier(path)) {
+          // Ideally, this should not happen
+          // it happens in these places now -
+          // case 1: Export Statements
+          // This is a bug in babel
+          // https://github.com/babel/babel/pull/3629
+          // case 2: Replacements in other plugins
+          // eg: https://github.com/babel/babili/issues/122
+          // replacement in dce from `x` to `!x` gives referencePath as `!x`
+          path.traverse({
+            ReferencedIdentifier(refPath) {
+              if (refPath.node.name === oldName && refPath.scope === scope) {
+                refPath.node.name = newName;
+              }
+            }
+          });
+        } else if (!isLabelIdentifier(path)) {
           node.name = newName;
         }
       }
diff --git a/packages/babel-preset-babili/__tests__/preset-tests.js b/packages/babel-preset-babili/__tests__/preset-tests.js
new file mode 100644
index 000000000..ef4e53f3c
--- /dev/null
+++ b/packages/babel-preset-babili/__tests__/preset-tests.js
@@ -0,0 +1,42 @@
+jest.autoMockOff();
+
+const babel = require("babel-core");
+const unpad = require("../../../utils/unpad");
+
+function transform(code, options = {}, sourceType = "script") {
+  return babel.transform(code,  {
+    sourceType,
+    minified: false,
+    presets: [
+      require("../src/index")
+    ],
+  }).code;
+}
+
+describe("preset", () => {
+  // https://github.com/babel/babili/issues/122
+  it ("should fix issue#122", () => {
+    const source = unpad(`
+      function foo() {
+        var a, b, c;
+        if (a) {
+          if (b) {
+            if (c) {}
+          }
+        } else {
+          if (b) {
+          } else {
+            if (c) {}
+          }
+        }
+      }
+    `);
+    const expected = unpad(`
+      function foo() {
+        var d, e, f;
+        d ? e && f : !b && f;
+      }
+    `);
+    expect(transform(source)).toBe(expected);
+  });
+});