diff --git a/spec/parser/javascript/subexp_spec.js b/spec/parser/javascript/subexp_spec.js
index cd55938..3ae6194 100644
--- a/spec/parser/javascript/subexp_spec.js
+++ b/spec/parser/javascript/subexp_spec.js
@@ -13,12 +13,21 @@ describe('parser/javascript/subexp.js', function() {
     '(test)': {
       regexp: jasmine.objectContaining({ textValue: 'test' })
     },
+    '(?<name>test)': {
+      regexp: jasmine.objectContaining({ textValue: 'test' })
+    },
     '(?=test)': {
       regexp: jasmine.objectContaining({ textValue: 'test' })
     },
     '(?!test)': {
       regexp: jasmine.objectContaining({ textValue: 'test' })
     },
+    '(?<=test)': {
+      regexp: jasmine.objectContaining({ textValue: 'test' })
+    },
+    '(?<!test)': {
+      regexp: jasmine.objectContaining({ textValue: 'test' })
+    },
     '(?:test)': {
       regexp: jasmine.objectContaining({ textValue: 'test' }),
       proxy: jasmine.objectContaining({ textValue: 'test' })
@@ -66,7 +75,7 @@ describe('parser/javascript/subexp.js', function() {
       this.node = new javascript.Parser('(test)').__consume__subexp();
       this.node.regexp = jasmine.createSpyObj('regexp', ['render']);
       this.node.container = jasmine.createSpyObj('container', ['addClass', 'group']);
-      spyOn(this.node, 'label').and.returnValue('example label')
+      spyOn(this.node, 'label').and.returnValue('example label');
 
       this.node.regexp.render.and.returnValue(this.renderDeferred.promise);
     });
@@ -95,6 +104,10 @@ describe('parser/javascript/subexp.js', function() {
         label: 'group #1',
         groupCounter: 2
       },
+      '(?<name>test)': {
+        label: 'group \'name\'',
+        groupCounter: 1
+      },
       '(?=test)': {
         label: 'positive lookahead',
         groupCounter: 1
@@ -103,6 +116,14 @@ describe('parser/javascript/subexp.js', function() {
         label: 'negative lookahead',
         groupCounter: 1
       },
+      '(?<=test)': {
+        label: 'positive lookbehind',
+        groupCounter: 1
+      },
+      '(?<!test)': {
+        label: 'negative lookbehind',
+        groupCounter: 1
+      },
       '(?:test)': {
         label: '',
         groupCounter: 1
diff --git a/src/js/parser/javascript/grammar.peg b/src/js/parser/javascript/grammar.peg
index cdc84c7..26495fc 100644
--- a/src/js/parser/javascript/grammar.peg
+++ b/src/js/parser/javascript/grammar.peg
@@ -11,7 +11,10 @@ grammar JavascriptRegexp
   repeat_spec <- ( "{" min:[0-9]+ "," max:[0-9]+ "}"
                  / "{" min:[0-9]+ ",}"
                  / "{" exact:[0-9]+ "}" ) <RepeatSpec>
-  subexp <- "(" capture:( "?:" / "?=" / "?!" )? regexp ")" <Subexp>
+  subexp <- "(" capture:( "?<" groupname:name ">" / "?:" / "?=" / "?!" / "?<=" / "?<!" )? regexp ")" <Subexp>
+  name <- alpha (alpha / numeric)*
+  alpha <- [a-zA-Z]
+  numeric <- [0-9]
   charset <- "[" invert:"^"? parts:( charset_range / charset_terminal )* "]" <Charset>
   charset_range <- first:charset_range_terminal "-" last:charset_range_terminal <CharsetRange>
   charset_terminal <- charset_escape <CharsetEscape>
diff --git a/src/js/parser/javascript/subexp.js b/src/js/parser/javascript/subexp.js
index 9f97811..b91f857 100644
--- a/src/js/parser/javascript/subexp.js
+++ b/src/js/parser/javascript/subexp.js
@@ -26,7 +26,9 @@ export default {
   labelMap: {
     '?:': '',
     '?=': 'positive lookahead',
-    '?!': 'negative lookahead'
+    '?!': 'negative lookahead',
+    '?<=': 'positive lookbehind',
+    '?<!': 'negative lookbehind'
   },
 
   // Renders the subexp into the currently set container.
@@ -48,6 +50,10 @@ export default {
   label() {
     if (_.has(this.labelMap, this.properties.capture.textValue)) {
       return this.labelMap[this.properties.capture.textValue];
+    } else if (this.properties.capture !== undefined
+      && this.properties.capture.properties !== undefined
+      && this.properties.capture.properties.groupname) {
+      return `group '${this.properties.capture.properties.groupname.textValue}'`;
     } else {
       return `group #${this.state.groupCounter++}`;
     }
@@ -59,7 +65,7 @@ export default {
     this.regexp = this.properties.regexp;
 
     // If there is no need for a label, then proxy to the nested regexp.
-    if (this.properties.capture.textValue == '?:') {
+    if (this.properties.capture.textValue === '?:') {
       this.proxy = this.regexp;
     }
   }