diff --git a/pkg/apis/core/validation/validation.go b/pkg/apis/core/validation/validation.go
index 6a4ae98dc9e..332f668084e 100644
--- a/pkg/apis/core/validation/validation.go
+++ b/pkg/apis/core/validation/validation.go
@@ -4966,3 +4966,13 @@ func ValidateCIDR(cidr string) (*net.IPNet, error) {
 	}
 	return net, nil
 }
+
+func IsDecremented(update, old *int32) bool {
+	if update == nil && old != nil {
+		return true
+	}
+	if update == nil || old == nil {
+		return false
+	}
+	return *update < *old
+}
diff --git a/pkg/apis/extensions/validation/validation.go b/pkg/apis/extensions/validation/validation.go
index 20cc279e8fd..a1f9aee6dc4 100644
--- a/pkg/apis/extensions/validation/validation.go
+++ b/pkg/apis/extensions/validation/validation.go
@@ -96,7 +96,7 @@ func validateDaemonSetStatus(status *extensions.DaemonSetStatus, fldPath *field.
 func ValidateDaemonSetStatusUpdate(ds, oldDS *extensions.DaemonSet) field.ErrorList {
 	allErrs := apivalidation.ValidateObjectMetaUpdate(&ds.ObjectMeta, &oldDS.ObjectMeta, field.NewPath("metadata"))
 	allErrs = append(allErrs, validateDaemonSetStatus(&ds.Status, field.NewPath("status"))...)
-	if isDecremented(ds.Status.CollisionCount, oldDS.Status.CollisionCount) {
+	if apivalidation.IsDecremented(ds.Status.CollisionCount, oldDS.Status.CollisionCount) {
 		value := int32(0)
 		if ds.Status.CollisionCount != nil {
 			value = *ds.Status.CollisionCount
@@ -341,7 +341,7 @@ func ValidateDeploymentStatusUpdate(update, old *extensions.Deployment) field.Er
 	allErrs := apivalidation.ValidateObjectMetaUpdate(&update.ObjectMeta, &old.ObjectMeta, field.NewPath("metadata"))
 	fldPath := field.NewPath("status")
 	allErrs = append(allErrs, ValidateDeploymentStatus(&update.Status, fldPath)...)
-	if isDecremented(update.Status.CollisionCount, old.Status.CollisionCount) {
+	if apivalidation.IsDecremented(update.Status.CollisionCount, old.Status.CollisionCount) {
 		value := int32(0)
 		if update.Status.CollisionCount != nil {
 			value = *update.Status.CollisionCount
@@ -351,17 +351,6 @@ func ValidateDeploymentStatusUpdate(update, old *extensions.Deployment) field.Er
 	return allErrs
 }
 
-// TODO: Move in "k8s.io/kubernetes/pkg/apis/core/validation"
-func isDecremented(update, old *int32) bool {
-	if update == nil && old != nil {
-		return true
-	}
-	if update == nil || old == nil {
-		return false
-	}
-	return *update < *old
-}
-
 func ValidateDeployment(obj *extensions.Deployment) field.ErrorList {
 	allErrs := apivalidation.ValidateObjectMeta(&obj.ObjectMeta, true, ValidateDeploymentName, field.NewPath("metadata"))
 	allErrs = append(allErrs, ValidateDeploymentSpec(&obj.Spec, field.NewPath("spec"))...)