diff --git a/pkg/registry/core/service/ipallocator/allocator.go b/pkg/registry/core/service/ipallocator/allocator.go
index fe25a30212c..dd206eb1d00 100644
--- a/pkg/registry/core/service/ipallocator/allocator.go
+++ b/pkg/registry/core/service/ipallocator/allocator.go
@@ -40,11 +40,18 @@ type Interface interface {
 
 var (
 	ErrFull              = errors.New("range is full")
-	ErrNotInRange        = errors.New("provided IP is not in the valid range")
 	ErrAllocated         = errors.New("provided IP is already allocated")
 	ErrMismatchedNetwork = errors.New("the provided network does not match the current range")
 )
 
+type ErrNotInRange struct {
+	ValidRange string
+}
+
+func (e *ErrNotInRange) Error() string {
+	return fmt.Sprintf("provided IP is not in the valid range. The range of valid IPs is %s", e.ValidRange)
+}
+
 // Range is a contiguous block of IPs that can be allocated atomically.
 //
 // The internal structure of the range is:
@@ -135,7 +142,7 @@ func (r *Range) CIDR() net.IPNet {
 func (r *Range) Allocate(ip net.IP) error {
 	ok, offset := r.contains(ip)
 	if !ok {
-		return ErrNotInRange
+		return &ErrNotInRange{r.net.String()}
 	}
 
 	allocated, err := r.alloc.Allocate(offset)
diff --git a/pkg/registry/core/service/ipallocator/allocator_test.go b/pkg/registry/core/service/ipallocator/allocator_test.go
index 1b6156feb91..ff854ce31b9 100644
--- a/pkg/registry/core/service/ipallocator/allocator_test.go
+++ b/pkg/registry/core/service/ipallocator/allocator_test.go
@@ -78,16 +78,19 @@ func TestAllocate(t *testing.T) {
 	if err := r.Release(released); err != nil {
 		t.Fatal(err)
 	}
-	if err := r.Allocate(net.ParseIP("192.168.0.1")); err != ErrNotInRange {
+	err = r.Allocate(net.ParseIP("192.168.0.1"))
+	if _, ok := err.(*ErrNotInRange); !ok {
 		t.Fatal(err)
 	}
 	if err := r.Allocate(net.ParseIP("192.168.1.1")); err != ErrAllocated {
 		t.Fatal(err)
 	}
-	if err := r.Allocate(net.ParseIP("192.168.1.0")); err != ErrNotInRange {
+	err = r.Allocate(net.ParseIP("192.168.1.0"))
+	if _, ok := err.(*ErrNotInRange); !ok {
 		t.Fatal(err)
 	}
-	if err := r.Allocate(net.ParseIP("192.168.1.255")); err != ErrNotInRange {
+	err = r.Allocate(net.ParseIP("192.168.1.255"))
+	if _, ok := err.(*ErrNotInRange); !ok {
 		t.Fatal(err)
 	}
 	if f := r.Free(); f != 1 {
diff --git a/pkg/registry/core/service/ipallocator/controller/repair.go b/pkg/registry/core/service/ipallocator/controller/repair.go
index df46a871285..7e13115f1f0 100644
--- a/pkg/registry/core/service/ipallocator/controller/repair.go
+++ b/pkg/registry/core/service/ipallocator/controller/repair.go
@@ -154,7 +154,7 @@ func (c *Repair) runOnce() error {
 			// TODO: send event
 			// cluster IP is duplicate
 			runtime.HandleError(fmt.Errorf("the cluster IP %s for service %s/%s was assigned to multiple services; please recreate", ip, svc.Name, svc.Namespace))
-		case ipallocator.ErrNotInRange:
+		case err.(*ipallocator.ErrNotInRange):
 			// TODO: send event
 			// cluster IP is out of range
 			runtime.HandleError(fmt.Errorf("the cluster IP %s for service %s/%s is not within the service CIDR %s; please recreate", ip, svc.Name, svc.Namespace, c.network))
diff --git a/pkg/registry/core/service/ipallocator/storage/storage_test.go b/pkg/registry/core/service/ipallocator/storage/storage_test.go
index efb1dfa6e01..cd4e34c3230 100644
--- a/pkg/registry/core/service/ipallocator/storage/storage_test.go
+++ b/pkg/registry/core/service/ipallocator/storage/storage_test.go
@@ -78,7 +78,8 @@ func TestEmpty(t *testing.T) {
 func TestErrors(t *testing.T) {
 	_, storage, _, _, destroyFunc := newStorage(t)
 	defer destroyFunc()
-	if err := storage.Allocate(net.ParseIP("192.168.0.0")); err != ipallocator.ErrNotInRange {
+	err := storage.Allocate(net.ParseIP("192.168.0.0"))
+	if _, ok := err.(*ipallocator.ErrNotInRange); !ok {
 		t.Fatal(err)
 	}
 }