diff --git a/lib/6to5/types/index.js b/lib/6to5/types/index.js
index 8fe0e48714..f11ed92e33 100644
--- a/lib/6to5/types/index.js
+++ b/lib/6to5/types/index.js
@@ -590,7 +590,7 @@ t.getBindingIdentifiers = function (node) {
 
     if (t.isIdentifier(id)) {
       ids[id.name] = id;
-    } else if (t.isModuleSpecifier(id)) {
+    } else if (t.isImportSpecifier(id)) {
       search.push(id.name || id.id);
     } else if (t.isExportDeclaration(id)) {
       if (t.isDeclaration(node.declaration)) {