diff --git a/lib/6to5/types/index.js b/lib/6to5/types/index.js
index a2b4445c00..012bb267e6 100644
--- a/lib/6to5/types/index.js
+++ b/lib/6to5/types/index.js
@@ -423,6 +423,10 @@ t.buildMatchMemberExpression = function (match, allowPartial) {
     while (search.length) {
       var node = search.shift();
 
+      if (allowPartial && i === parts.length) {
+        return true;
+      }
+
       if (t.isIdentifier(node)) {
         // this part doesn't match
         if (parts[i] !== node.name) return false;
@@ -444,8 +448,8 @@ t.buildMatchMemberExpression = function (match, allowPartial) {
       }
 
       // too many parts
-      if (++i >= parts.length) {
-        return !!allowPartial;
+      if (++i > parts.length) {
+        return false;
       }
     }