diff --git a/consul/catalog_endpoint.go b/consul/catalog_endpoint.go
index 4abe02584..a5b674869 100644
--- a/consul/catalog_endpoint.go
+++ b/consul/catalog_endpoint.go
@@ -90,11 +90,13 @@ func (c *Catalog) Register(args *structs.RegisterRequest, reply *struct{}) error
 		}
 	}
 
-	_, err = c.srv.raftApply(structs.RegisterRequestType, args)
+	resp, err := c.srv.raftApply(structs.RegisterRequestType, args)
 	if err != nil {
 		return err
 	}
-
+	if respErr, ok := resp.(error); ok {
+		return respErr
+	}
 	return nil
 }
 
diff --git a/consul/state/catalog.go b/consul/state/catalog.go
index ca5eb6110..bbfddb23b 100644
--- a/consul/state/catalog.go
+++ b/consul/state/catalog.go
@@ -165,22 +165,45 @@ func (s *StateStore) EnsureNode(idx uint64, node *structs.Node) error {
 // registration or modify an existing one in the state store. It allows
 // passing in a memdb transaction so it may be part of a larger txn.
 func (s *StateStore) ensureNodeTxn(tx *memdb.Txn, idx uint64, node *structs.Node) error {
-	// Check for an existing node
-	existing, err := tx.First("nodes", "id", node.Node)
-	if err != nil {
-		return fmt.Errorf("node name lookup failed: %s", err)
+	// See if there's an existing node with this UUID, and make sure the
+	// name is the same.
+	var n *structs.Node
+	if node.ID != "" {
+		existing, err := tx.First("nodes", "uuid", string(node.ID))
+		if err != nil {
+			return fmt.Errorf("node lookup failed: %s", err)
+		}
+		if existing != nil {
+			n = existing.(*structs.Node)
+			fmt.Printf("XXX %#v\n", *n)
+			if n.Node != node.Node {
+				return fmt.Errorf("node ID %q for node %q aliases existing node %q",
+					node.ID, node.Node, n.Node)
+			}
+		}
 	}
 
-	// Get the indexes
-	if existing != nil {
-		node.CreateIndex = existing.(*structs.Node).CreateIndex
+	// Check for an existing node by name to support nodes with no IDs.
+	if n == nil {
+		existing, err := tx.First("nodes", "id", node.Node)
+		if err != nil {
+			return fmt.Errorf("node name lookup failed: %s", err)
+		}
+		if existing != nil {
+			n = existing.(*structs.Node)
+		}
+	}
+
+	// Get the indexes.
+	if n != nil {
+		node.CreateIndex = n.CreateIndex
 		node.ModifyIndex = idx
 	} else {
 		node.CreateIndex = idx
 		node.ModifyIndex = idx
 	}
 
-	// Insert the node and update the index
+	// Insert the node and update the index.
 	if err := tx.Insert("nodes", node); err != nil {
 		return fmt.Errorf("failed inserting node: %s", err)
 	}
diff --git a/consul/state/catalog_test.go b/consul/state/catalog_test.go
index 88dcff5a8..21bf59ab6 100644
--- a/consul/state/catalog_test.go
+++ b/consul/state/catalog_test.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"reflect"
 	"sort"
+	"strings"
 	"testing"
 
 	"github.com/hashicorp/consul/consul/structs"
@@ -419,6 +420,23 @@ func TestStateStore_EnsureNode(t *testing.T) {
 	if idx != 3 {
 		t.Fatalf("bad index: %d", idx)
 	}
+
+	// Add an ID to the node
+	in.ID = types.NodeID("cda916bc-a357-4a19-b886-59419fcee50c")
+	if err := s.EnsureNode(4, in); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Now try to add another node with the same ID
+	in = &structs.Node{
+		Node:    "nope",
+		ID:      types.NodeID("cda916bc-a357-4a19-b886-59419fcee50c"),
+		Address: "1.2.3.4",
+	}
+	err = s.EnsureNode(5, in)
+	if err == nil || !strings.Contains(err.Error(), "aliases existing node") {
+		t.Fatalf("err: %v", err)
+	}
 }
 
 func TestStateStore_GetNodes(t *testing.T) {