diff --git a/src/ng/directive/input.js b/src/ng/directive/input.js
index 6b67b8198a3f..f5a9b2e4c220 100644
--- a/src/ng/directive/input.js
+++ b/src/ng/directive/input.js
@@ -1161,9 +1161,6 @@ function badInputChecker(scope, element, attr, ctrl) {
 }
 
 function numberInputType(scope, element, attr, ctrl, $sniffer, $browser) {
-  badInputChecker(scope, element, attr, ctrl);
-  baseInputType(scope, element, attr, ctrl, $sniffer, $browser);
-
   ctrl.$$parserName = 'number';
   ctrl.$parsers.push(function(value) {
     if (ctrl.$isEmpty(value))      return null;
@@ -1171,6 +1168,9 @@ function numberInputType(scope, element, attr, ctrl, $sniffer, $browser) {
     return undefined;
   });
 
+  badInputChecker(scope, element, attr, ctrl);
+  baseInputType(scope, element, attr, ctrl, $sniffer, $browser);
+
   ctrl.$formatters.push(function(value) {
     if (!ctrl.$isEmpty(value)) {
       if (!isNumber(value)) {
diff --git a/test/ng/directive/inputSpec.js b/test/ng/directive/inputSpec.js
index a50c1640cfc5..e3f80a1701c7 100644
--- a/test/ng/directive/inputSpec.js
+++ b/test/ng/directive/inputSpec.js
@@ -1140,10 +1140,8 @@ describe('ngModel', function() {
 
     dealoc(element);
   }));
-
 });
 
-
 describe('input', function() {
   var formElm, inputElm, scope, $compile, $sniffer, $browser, changeInputValueTo, currentSpec;
 
@@ -2209,7 +2207,6 @@ describe('input', function() {
       compileInput('<input type="text" name="input" ng-model="value" minlength="3" />');
       expect(scope.value).toBe('12345');
     });
-
   });
 
 
@@ -3387,7 +3384,6 @@ describe('input', function() {
       expect(inputElm).toBeInvalid();
     });
 
-
     it('should render as blank if null', function() {
       compileInput('<input type="number" ng-model="age" />');
 
@@ -3408,7 +3404,6 @@ describe('input', function() {
       expect(inputElm.val()).toBe('');
     });
 
-
     it('should parse empty string to null', function() {
       compileInput('<input type="number" ng-model="age" />');
 
@@ -3419,7 +3414,6 @@ describe('input', function() {
       expect(inputElm).toBeValid();
     });
 
-
     it('should only invalidate the model if suffering from bad input when the data is parsed', function() {
       compileInput('<input type="number" ng-model="age" />', {
         valid: false,
@@ -3435,7 +3429,6 @@ describe('input', function() {
       expect(inputElm).toBeInvalid();
     });
 
-
     it('should validate number if transition from bad input to empty string', function() {
       var validity = {
         valid: false,
@@ -3450,6 +3443,18 @@ describe('input', function() {
       expect(inputElm).toBeValid();
     });
 
+    it('should be valid when no value has been set even if it is validated', function() {
+      // This situation isn't common, but it does arise, when other directives
+      // on the same element observe an attribute (e.g. ngRequired, min, max etc).
+
+      compileInput('<input type="number" name="alias" ng-model="value" />');
+
+      scope.form.alias.$validate();
+
+      expect(inputElm).toBeValid();
+      expect(scope.form.alias.$error.number).toBeFalsy();
+    });
+
     it('should throw if the model value is not a number', function() {
       expect(function() {
         scope.value = 'one';
@@ -3457,7 +3462,6 @@ describe('input', function() {
       }).toThrowMinErr('ngModel', 'numfmt', "Expected `one` to be a number");
     });
 
-
     describe('min', function() {
 
       it('should validate', function() {
@@ -3540,7 +3544,6 @@ describe('input', function() {
       });
     });
 
-
     describe('max', function() {
 
       it('should validate', function() {
@@ -3623,7 +3626,6 @@ describe('input', function() {
       });
     });
 
-
     describe('required', function() {
 
       it('should be valid even if value is 0', function() {
@@ -3655,6 +3657,102 @@ describe('input', function() {
       });
     });
 
+    describe('ngRequired', function() {
+
+      describe('when the ngRequired expression initially evaluates to true', function() {
+
+        it('should be valid even if value is 0', function() {
+          compileInput('<input type="number" ng-model="value" name="alias" ng-required="true" />');
+
+          changeInputValueTo('0');
+          expect(inputElm).toBeValid();
+          expect(scope.value).toBe(0);
+          expect(scope.form.alias.$error.required).toBeFalsy();
+        });
+
+        it('should be valid even if value 0 is set from model', function() {
+          compileInput('<input type="number" ng-model="value" name="alias" ng-required="true" />');
+
+          scope.$apply('value = 0');
+
+          expect(inputElm).toBeValid();
+          expect(inputElm.val()).toBe('0');
+          expect(scope.form.alias.$error.required).toBeFalsy();
+        });
+
+        it('should register required on non boolean elements', function() {
+          compileInput('<div ng-model="value" name="alias" ng-required="true">');
+
+          scope.$apply("value = ''");
+
+          expect(inputElm).toBeInvalid();
+          expect(scope.form.alias.$error.required).toBeTruthy();
+        });
+
+        it('should change from invalid to valid when the value is empty and the ngRequired expression changes to false', function() {
+          compileInput('<input type="number" ng-model="value" name="alias" ng-required="ngRequiredExpr" />');
+
+          scope.$apply('ngRequiredExpr = true');
+
+          expect(inputElm).toBeInvalid();
+          expect(scope.value).toBeUndefined();
+          expect(scope.form.alias.$error.required).toBeTruthy();
+
+          scope.$apply('ngRequiredExpr = false');
+
+          expect(inputElm).toBeValid();
+          expect(scope.value).toBeNull();
+          expect(scope.form.alias.$error.required).toBeFalsy();
+        });
+      });
+
+      describe('when the ngRequired expression initially evaluates to false', function() {
+
+        it('should be valid even if value is empty', function() {
+          compileInput('<input type="number" ng-model="value" name="alias" ng-required="false" />');
+
+          expect(inputElm).toBeValid();
+          expect(scope.value).toBeNull();
+          expect(scope.form.alias.$error.required).toBeFalsy();
+          expect(scope.form.alias.$error.number).toBeFalsy();
+        });
+
+        it('should be valid if value is non-empty', function() {
+          compileInput('<input type="number" ng-model="value" name="alias" ng-required="false" />');
+
+          changeInputValueTo('42');
+          expect(inputElm).toBeValid();
+          expect(scope.value).toBe(42);
+          expect(scope.form.alias.$error.required).toBeFalsy();
+        });
+
+        it('should not register required on non boolean elements', function() {
+          compileInput('<div ng-model="value" name="alias" ng-required="false">');
+
+          scope.$apply("value = ''");
+
+          expect(inputElm).toBeValid();
+          expect(scope.form.alias.$error.required).toBeFalsy();
+        });
+
+        it('should change from valid to invalid when the value is empty and the ngRequired expression changes to true', function() {
+          compileInput('<input type="number" ng-model="value" name="alias" ng-required="ngRequiredExpr" />');
+
+          scope.$apply('ngRequiredExpr = false');
+
+          expect(inputElm).toBeValid();
+          expect(scope.value).toBeNull();
+          expect(scope.form.alias.$error.required).toBeFalsy();
+
+          scope.$apply('ngRequiredExpr = true');
+
+          expect(inputElm).toBeInvalid();
+          expect(scope.value).toBeUndefined();
+          expect(scope.form.alias.$error.required).toBeTruthy();
+        });
+      });
+    });
+
     describe('minlength', function() {
 
       it('should invalidate values that are shorter than the given minlength', function() {
@@ -3700,7 +3798,6 @@ describe('input', function() {
       });
     });
 
-
     describe('maxlength', function() {
 
       it('should invalidate values that are longer than the given maxlength', function() {