diff --git a/consul/key_client.go b/consul/key_client.go
index b95f3705..22254f3e 100644
--- a/consul/key_client.go
+++ b/consul/key_client.go
@@ -88,6 +88,19 @@ func (c *keyClient) Cas(path, value string, flags int, cas int) (bool, error) {
 	return written, nil
 }
 
+func (c *keyClient) DeleteCas(path string, cas int) (bool, error) {
+	log.Printf(
+		"[DEBUG] Deleting key '%s' in %s with cas %d",
+		path, c.wOpts.Datacenter, cas,
+	)
+	pair := consulapi.KVPair{Key: path, ModifyIndex: uint64(cas)}
+	written, _, err := c.client.DeleteCAS(&pair, c.wOpts)
+	if err != nil {
+		return false, fmt.Errorf("failed to delete Consul key '%s': %s", path, err)
+	}
+	return written, nil
+}
+
 func (c *keyClient) Delete(path string) error {
 	log.Printf(
 		"[DEBUG] Deleting key '%s' in %s",
diff --git a/consul/resource_consul_keys.go b/consul/resource_consul_keys.go
index 9506075e..7e984141 100644
--- a/consul/resource_consul_keys.go
+++ b/consul/resource_consul_keys.go
@@ -158,7 +158,7 @@ func resourceConsulKeysCreateUpdate(d *schema.ResourceData, meta interface{}) er
 
 			flags := sub["flags"].(int)
 			cas := sub["cas"].(int)
-			if cas != -1 {
+			if cas >= 0 {
 				_, err := keyClient.Cas(path, value, flags, cas)
 				if err != nil {
 					return err
@@ -273,7 +273,14 @@ func resourceConsulKeysDelete(d *schema.ResourceData, meta interface{}) error {
 		if !ok || !shouldDelete {
 			continue
 		}
-
+		cas := sub["cas"].(int)
+		if cas > 0 {
+			_, err := keyClient.DeleteCas(path, cas)
+			if err != nil {
+				return err
+			}
+			continue
+		}
 		if err := keyClient.Delete(path); err != nil {
 			return err
 		}