diff --git a/Gopkg.lock b/Gopkg.lock
index 2125a89..f869e1a 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -10,7 +10,7 @@
     "request",
     "sdk"
   ]
-  revision = "f0bad5cda5e5c9bfb9cca1f78f551486b8f30afb"
+  revision = "5fd6750b50f03d491b794e178fe5fce311a721b7"
   source = "github.com/stelcheck/ncloud-sdk-go"
 
 [[projects]]
@@ -68,8 +68,8 @@
     "service/s3",
     "service/sts"
   ]
-  revision = "c7cd1ebe87257cde9b65112fc876b0339ea0ac30"
-  version = "v1.13.49"
+  revision = "ee7b4b1162937cba700de23bd90acb742982e626"
+  version = "v1.13.50"
 
 [[projects]]
   branch = "master"
diff --git a/src/terraform-provider-ncloud/resource_instance.go b/src/terraform-provider-ncloud/resource_instance.go
index d21d551..948c950 100644
--- a/src/terraform-provider-ncloud/resource_instance.go
+++ b/src/terraform-provider-ncloud/resource_instance.go
@@ -60,6 +60,13 @@ func resourceInstance() *schema.Resource {
 				Description: "script to run at first boot",
 				Default:     false,
 			},
+			"public_ip_instance": &schema.Schema{
+				Type:        schema.TypeString,
+				Optional:    true,
+				ForceNew:    true,
+				Description: "Public IP ID",
+				Default:     "",
+			},
 			"public_ip": &schema.Schema{
 				Type:     schema.TypeString,
 				Computed: true,
@@ -120,6 +127,19 @@ func resourceInstanceCreate(data *schema.ResourceData, meta interface{}) error {
 
 	waitForServerStatus(client, data.Id(), "RUN")
 
+	publicIP := data.Get("public_ip_instance").(string)
+	if publicIP != "" {
+		associateReqParams := new(sdk.RequestAssociatePublicIP)
+		associateReqParams.PublicIPInstanceNo = publicIP
+		associateReqParams.ServerInstanceNo = data.Id()
+
+		_, err = client.AssociatePublicIP(associateReqParams)
+		if err != nil {
+			return fmt.Errorf("Failed to associate public IP %s", err)
+		}
+	}
+	data.SetPartial("public_ip_instance")
+
 	return resourceInstanceRead(data, meta)
 }
 
@@ -160,6 +180,8 @@ func resourceInstanceDelete(data *schema.ResourceData, meta interface{}) error {
 				return fmt.Errorf("Failed to disassociate IP with ID %s from server %s: %s", publicIP, data.Id(), err)
 			}
 
+			waitForPublicIPDetach(client, publicIPInstance.PublicIPInstanceNo)
+
 			break
 		}
 	}
diff --git a/src/terraform-provider-ncloud/resource_public_ip.go b/src/terraform-provider-ncloud/resource_public_ip.go
index 4340759..88c4b5a 100644
--- a/src/terraform-provider-ncloud/resource_public_ip.go
+++ b/src/terraform-provider-ncloud/resource_public_ip.go
@@ -15,12 +15,6 @@ func resourcePublicIP() *schema.Resource {
 		Read:   resourcePublicIPRead,
 		Delete: resourcePublicIPDelete,
 		Schema: map[string]*schema.Schema{
-			"server_id": &schema.Schema{
-				Type:        schema.TypeString,
-				ForceNew:    true,
-				Required:    true,
-				Description: "Product code (see https://github.com/Wizcorp/terraform-provider-ncloud/blob/master/Services.md#servers-server_product_code)",
-			},
 			"public_ip": &schema.Schema{
 				Type:     schema.TypeString,
 				Computed: true,
@@ -33,8 +27,6 @@ func resourcePublicIPCreate(data *schema.ResourceData, meta interface{}) error {
 	client := meta.(*sdk.Conn)
 	data.Partial(true)
 
-	serverID := data.Get("server_id").(string)
-
 	readReqParams := new(sdk.RequestGetServerInstanceList)
 
 	readResponse, err := client.GetServerInstanceList(readReqParams)
@@ -49,7 +41,6 @@ func resourcePublicIPCreate(data *schema.ResourceData, meta interface{}) error {
 	serverInfo := readResponse.ServerInstanceList[0]
 
 	reqParams := new(sdk.RequestCreatePublicIPInstance)
-	reqParams.ServerInstanceNo = serverID
 	reqParams.RegionNo = serverInfo.Region.RegionNo
 	// API doc says we should be allowed to specify th zone
 	// reqParams.ZoneNo = serverInfo.Zone.ZoneNo
@@ -65,7 +56,6 @@ func resourcePublicIPCreate(data *schema.ResourceData, meta interface{}) error {
 
 	ipInfo := response.PublicIPInstanceList[0]
 	data.SetId(ipInfo.PublicIPInstanceNo)
-	data.SetPartial("server_id")
 
 	return resourcePublicIPRead(data, meta)
 }