diff --git a/lib/nodes.js b/lib/nodes.js
index ecd2c718..11310622 100644
--- a/lib/nodes.js
+++ b/lib/nodes.js
@@ -1144,7 +1144,7 @@
     }
     Assign.prototype.children = ['variable', 'value'];
     Assign.prototype.isStatement = function(o) {
-      return (o != null ? o.level : void 0) === LEVEL_TOP && __indexOf.call(this.context, "?") >= 0;
+      return (o != null ? o.level : void 0) === LEVEL_TOP && (this.context != null) && __indexOf.call(this.context, "?") >= 0;
     };
     Assign.prototype.assigns = function(name) {
       return this[this.context === 'object' ? 'value' : 'variable'].assigns(name);
diff --git a/src/nodes.coffee b/src/nodes.coffee
index c40890ad..4e7afc3a 100644
--- a/src/nodes.coffee
+++ b/src/nodes.coffee
@@ -917,7 +917,7 @@ exports.Assign = class Assign extends Base
   children: ['variable', 'value']
 
   isStatement: (o) ->
-    o?.level is LEVEL_TOP and "?" in @context
+    o?.level is LEVEL_TOP and @context? and "?" in @context
 
   assigns: (name) ->
     @[if @context is 'object' then 'value' else 'variable'].assigns name