diff --git a/src/js/parser/javascript.js b/src/js/parser/javascript.js
index 7679bb2..48ce9f2 100644
--- a/src/js/parser/javascript.js
+++ b/src/js/parser/javascript.js
@@ -36,4 +36,8 @@ parser.Parser.RepeatOptional = RepeatOptional;
 parser.Parser.RepeatRequired = RepeatRequired;
 parser.Parser.RepeatSpec = RepeatSpec;
 
+parser.resetGroupCounter = () => {
+  parser.Parser.Subexp.resetCounter();
+}
+
 export default parser;
diff --git a/src/js/parser/javascript/subexp.js b/src/js/parser/javascript/subexp.js
index a796bbb..607b281 100644
--- a/src/js/parser/javascript/subexp.js
+++ b/src/js/parser/javascript/subexp.js
@@ -1,6 +1,8 @@
 import _ from 'lodash';
 import Base from './base.js';
 
+var groupCounter = 1;
+
 export default _.extend({}, Base, {
   type: 'subexp',
 
@@ -72,7 +74,11 @@ export default _.extend({}, Base, {
     if (_.has(this.labelMap, this._capture.textValue)) {
       return this.labelMap[this._capture.textValue];
     } else {
-      return 'group #TBA';
+      return 'group #' + (groupCounter++);
     }
-  }
+  },
+
+  resetCounter() {
+    groupCounter = 1;
+  },
 });
diff --git a/src/js/regexper.js b/src/js/regexper.js
index 6079a51..3134fcf 100644
--- a/src/js/regexper.js
+++ b/src/js/regexper.js
@@ -87,6 +87,8 @@ export default class Regexper {
 
     snap.selectAll('g').remove();
 
+    parser.resetGroupCounter();
+
     return Q.fcall(parser.parse.bind(parser), expression)
       .then((result) => {
         result.container = snap.group();