diff --git a/builtin/providers/aws/resource_aws_ecs_task_definition.go b/builtin/providers/aws/resource_aws_ecs_task_definition.go
index bdc260a41..fe28252f2 100644
--- a/builtin/providers/aws/resource_aws_ecs_task_definition.go
+++ b/builtin/providers/aws/resource_aws_ecs_task_definition.go
@@ -132,18 +132,39 @@ func resourceAwsEcsTaskDefinitionRead(d *schema.ResourceData, meta interface{})
 }
 
 func resourceAwsEcsTaskDefinitionUpdate(d *schema.ResourceData, meta interface{}) error {
-	return resourceAwsEcsTaskDefinitionCreate(d, meta)
+	oldArn := d.Get("arn").(string)
+
+	log.Printf("[DEBUG] Creating new revision of task definition %q", d.Id())
+	err := resourceAwsEcsTaskDefinitionCreate(d, meta)
+	if err != nil {
+		return err
+	}
+	log.Printf("[DEBUG] New revision of %q created: %q", d.Id(), d.Get("arn").(string))
+
+	log.Printf("[DEBUG] Deregistering old revision of task definition %q: %q", d.Id(), oldArn)
+	conn := meta.(*AWSClient).ecsconn
+	_, err = conn.DeregisterTaskDefinition(&ecs.DeregisterTaskDefinitionInput{
+		TaskDefinition: aws.String(oldArn),
+	})
+	if err != nil {
+		return err
+	}
+	log.Printf("[DEBUG] Old revision of task definition deregistered: %q", oldArn)
+
+	return resourceAwsEcsTaskDefinitionRead(d, meta)
 }
 
 func resourceAwsEcsTaskDefinitionDelete(d *schema.ResourceData, meta interface{}) error {
 	conn := meta.(*AWSClient).ecsconn
 
-	// NOT YET IMPLEMENTED o_O
 	_, err := conn.DeregisterTaskDefinition(&ecs.DeregisterTaskDefinitionInput{
-		TaskDefinition: aws.String(d.Id()),
+		TaskDefinition: aws.String(d.Get("arn").(string)),
 	})
+	if err != nil {
+		return err
+	}
 
-	log.Printf("[DEBUG] Deregistering task definition %s returned %#v", d.Id(), err)
+	log.Printf("[DEBUG] Task definition %q deregistered.", d.Get("arn").(string))
 
 	return nil
 }
diff --git a/builtin/providers/aws/resource_aws_ecs_task_definition_test.go b/builtin/providers/aws/resource_aws_ecs_task_definition_test.go
index df37eba4e..2cff051c5 100644
--- a/builtin/providers/aws/resource_aws_ecs_task_definition_test.go
+++ b/builtin/providers/aws/resource_aws_ecs_task_definition_test.go
@@ -22,6 +22,12 @@ func TestAccAWSEcsTaskDefinition_basic(t *testing.T) {
 					testAccCheckAWSEcsTaskDefinitionExists("aws_ecs_task_definition.jenkins"),
 				),
 			},
+			resource.TestStep{
+				Config: testAccAWSEcsTaskDefinitionModifier,
+				Check: resource.ComposeTestCheckFunc(
+					testAccCheckAWSEcsTaskDefinitionExists("aws_ecs_task_definition.jenkins"),
+				),
+			},
 		},
 	})
 }
@@ -63,7 +69,7 @@ func testAccCheckAWSEcsTaskDefinitionExists(name string) resource.TestCheckFunc
 
 var testAccAWSEcsTaskDefinition = `
 resource "aws_ecs_task_definition" "jenkins" {
-  family = "jenkins"
+  family = "terraform-acc-test"
   container_definitions = <<TASK_DEFINITION
 [
 	{
@@ -109,3 +115,52 @@ TASK_DEFINITION
   }
 }
 `
+
+var testAccAWSEcsTaskDefinitionModifier = `
+resource "aws_ecs_task_definition" "jenkins" {
+  family = "terraform-acc-test"
+  container_definitions = <<TASK_DEFINITION
+[
+	{
+		"cpu": 10,
+		"command": ["sleep", "10"],
+		"entryPoint": ["/"],
+		"environment": [
+			{"name": "VARNAME", "value": "VARVAL"}
+		],
+		"essential": true,
+		"image": "jenkins",
+		"links": ["mongodb"],
+		"memory": 128,
+		"name": "jenkins",
+		"portMappings": [
+			{
+				"containerPort": 80,
+				"hostPort": 8080
+			}
+		]
+	},
+	{
+		"cpu": 20,
+		"command": ["sleep", "10"],
+		"entryPoint": ["/"],
+		"essential": true,
+		"image": "mongodb",
+		"memory": 128,
+		"name": "mongodb",
+		"portMappings": [
+			{
+				"containerPort": 28017,
+				"hostPort": 28017
+			}
+		]
+	}
+]
+TASK_DEFINITION
+
+  volume {
+    name = "jenkins-home"
+    host_path = "/ecs/jenkins-home"
+  }
+}
+`
diff --git a/website/source/docs/providers/aws/r/ecs_task_definition.html.markdown b/website/source/docs/providers/aws/r/ecs_task_definition.html.markdown
index 0a265af4e..e89a81e1a 100644
--- a/website/source/docs/providers/aws/r/ecs_task_definition.html.markdown
+++ b/website/source/docs/providers/aws/r/ecs_task_definition.html.markdown
@@ -10,10 +10,6 @@ description: |-
 
 Provides an ECS task definition to be used in `aws_ecs_service`.
 
-~> **NOTE:** There is currently no way to unregister
-any previously registered task definition.
-See related [thread in AWS forum](https://forums.aws.amazon.com/thread.jspa?threadID=170378&tstart=0).
-
 ## Example Usage
 
 ```