diff --git a/src/state.js b/src/state.js
index 146cce228..24756a10b 100644
--- a/src/state.js
+++ b/src/state.js
@@ -778,6 +778,8 @@ function $StateProvider(   $urlRouterProvider,   $urlMatcherFactory) {
       }
       if (toState[abstractKey]) throw new Error("Cannot transition to abstract state '" + to + "'");
       if (options.inherit) toParams = inheritParams($stateParams, toParams || {}, $state.$current, toState);
+      if (!toState.params.$$validates(toParams)) return TransitionFailed;
+
       var defaultParams = toState.params.$$values();
       toParams = extend(defaultParams, toParams);
       to = toState;
diff --git a/src/urlMatcherFactory.js b/src/urlMatcherFactory.js
index 524c2db81..ebda4ca82 100644
--- a/src/urlMatcherFactory.js
+++ b/src/urlMatcherFactory.js
@@ -94,6 +94,14 @@ function UrlMatcher(pattern, config) {
     return result + flag + '(' + pattern + ')' + flag;
   }
 
+  function regexpType(regexp) {
+    var type = new Type({
+      pattern: new RegExp(regexp),
+      is: function(value) { return type.pattern.exec(type.encode(value)); }
+    });
+    return type;
+  }
+
   this.source = pattern;
 
   // Split into static segments separated by path parameter placeholders.
@@ -104,7 +112,7 @@ function UrlMatcher(pattern, config) {
     id      = m[2] || m[3]; // IE[78] returns '' for unmatched groups instead of null
     regexp  = m[4] || (m[1] == '*' ? '.*' : '[^/]*');
     segment = pattern.substring(last, m.index);
-    type    = this.$types[regexp] || new Type({ pattern: new RegExp(regexp) });
+    type    = this.$types[regexp] || regexpType(regexp);
     cfg     = config.params[id];
 
     if (segment.indexOf('?') >= 0) break; // we're into the search part
diff --git a/test/stateSpec.js b/test/stateSpec.js
index ed7c3a3a0..cd217dbfe 100644
--- a/test/stateSpec.js
+++ b/test/stateSpec.js
@@ -96,6 +96,9 @@ describe('state', function () {
       .state('badParam', {
         url: "/bad/{param:int}"
       })
+      .state('badParam2', {
+        url: "/bad2/{param:[0-9]{5}}"
+      })
 
       .state('first', { url: '^/first/subpath' })
       .state('second', { url: '^/second' })
@@ -755,6 +758,7 @@ describe('state', function () {
         'about.sidebar',
         'about.sidebar.item',
         'badParam',
+        'badParam2',
         'dynamicController',
         'first',
         'home',
@@ -875,6 +879,29 @@ describe('state', function () {
         $rootScope.$apply();
         expect($state.current.name).toBe("about");
       }));
+
+      it('should ignore bad state parameters', inject(function ($state, $rootScope, $location, $stateParams) {
+        $state.go("badParam", { param: 5 });
+        $rootScope.$apply();
+        expect($state.current.name).toBe("badParam");
+        expect($stateParams).toEqual({param: 5});
+
+        $state.go("badParam2", { param: '12345' }); // must be 5 digits
+        $rootScope.$apply();
+        expect($state.current.name).toBe("badParam2");
+
+        $state.go("about");
+        $rootScope.$apply();
+        expect($state.current.name).toBe('about');
+
+        $state.go("badParam", { param: 'foo' });
+        $rootScope.$apply();
+        expect($state.current.name).toBe("about");
+
+        $state.go("badParam2", { param: '1234' }); // must be 5 digits
+        $rootScope.$apply();
+        expect($state.current.name).toBe("about");
+      }));
     });
 
     it('should revert to last known working url on state change failure', inject(function ($state, $rootScope, $location, $q) {