diff --git a/js/compiler/compiler.js b/js/compiler/compiler.js
index d153266..716794f 100644
--- a/js/compiler/compiler.js
+++ b/js/compiler/compiler.js
@@ -366,7 +366,7 @@ semantics.addOperation('buildSubscription(mode)', {
     return ES5.translateNonterminalCode(children,
                                         function(n) {
                                           return n.buildSubscription(self.args.mode);
-                                        });
+                                        }) || this.interval.contents;
   }
 });
 
diff --git a/js/compiler/es5.js b/js/compiler/es5.js
index 5bd44e8..fa876e2 100644
--- a/js/compiler/es5.js
+++ b/js/compiler/es5.js
@@ -66,7 +66,8 @@ function translateNonterminalCode(children, nodeTranslator) {
 var modifiedSourceActions = {
   _nonterminal: function(children) {
     return translateNonterminalCode(children,
-                                    function(n) { return n.modifiedSource; });
+                                    function(n) { return n.modifiedSource; })
+      || this.interval.contents;
   },
   _iter: function(_) {
     throw new Error('_iter semantic action should never be hit');