diff --git a/builtin/providers/aws/data_source_aws_ecs_container_definition.go b/builtin/providers/aws/data_source_aws_ecs_container_definition.go
index df72f80e6..412019ac9 100644
--- a/builtin/providers/aws/data_source_aws_ecs_container_definition.go
+++ b/builtin/providers/aws/data_source_aws_ecs_container_definition.go
@@ -41,7 +41,7 @@ func dataSourceAwsEcsContainerDefinition() *schema.Resource {
 				Type:     schema.TypeInt,
 				Computed: true,
 			},
-			"memoryReservation": &schema.Schema{
+			"memory_reservation": &schema.Schema{
 				Type:     schema.TypeInt,
 				Computed: true,
 			},
@@ -88,7 +88,7 @@ func dataSourceAwsEcsContainerDefinitionRead(d *schema.ResourceData, meta interf
 		}
 		d.Set("cpu", aws.Int64Value(def.Cpu))
 		d.Set("memory", aws.Int64Value(def.Memory))
-		d.Set("memoryReservation", aws.Int64Value(def.MemoryReservation))
+		d.Set("memory_reservation", aws.Int64Value(def.MemoryReservation))
 		d.Set("disable_networking", aws.BoolValue(def.DisableNetworking))
 		d.Set("docker_labels", aws.StringValueMap(def.DockerLabels))
 
diff --git a/builtin/providers/aws/data_source_aws_ecs_container_definition_test.go b/builtin/providers/aws/data_source_aws_ecs_container_definition_test.go
index 271b5b835..0786d85f4 100644
--- a/builtin/providers/aws/data_source_aws_ecs_container_definition_test.go
+++ b/builtin/providers/aws/data_source_aws_ecs_container_definition_test.go
@@ -17,7 +17,7 @@ func TestAccAWSEcsDataSource_ecsContainerDefinition(t *testing.T) {
 					resource.TestCheckResourceAttr("data.aws_ecs_container_definition.mongo", "image", "mongo:latest"),
 					resource.TestCheckResourceAttr("data.aws_ecs_container_definition.mongo", "image_digest", "latest"),
 					resource.TestCheckResourceAttr("data.aws_ecs_container_definition.mongo", "memory", "128"),
-					resource.TestCheckResourceAttr("data.aws_ecs_container_definition.mongo", "memoryReservation", "64"),
+					resource.TestCheckResourceAttr("data.aws_ecs_container_definition.mongo", "memory_reservation", "64"),
 					resource.TestCheckResourceAttr("data.aws_ecs_container_definition.mongo", "cpu", "128"),
 					resource.TestCheckResourceAttr("data.aws_ecs_container_definition.mongo", "environment.SECRET", "KEY"),
 				),
diff --git a/website/source/docs/providers/aws/d/ecs_container_definition.html.markdown b/website/source/docs/providers/aws/d/ecs_container_definition.html.markdown
index 6badc81dd..5f8dac6df 100644
--- a/website/source/docs/providers/aws/d/ecs_container_definition.html.markdown
+++ b/website/source/docs/providers/aws/d/ecs_container_definition.html.markdown
@@ -35,6 +35,7 @@ The following attributes are exported:
 * `image_digest` - The digest of the docker image in use
 * `cpu` - The CPU limit for this container definition
 * `memory` - The memory limit for this container definition
+* `memory_reservation` - The soft limit (in MiB) of memory to reserve for the container. When system memory is under contention, Docker attempts to keep the container memory to this soft limit
 * `environment` - The environment in use
 * `disable_networking` - Indicator if networking is disabled
 * `docker_labels` - Set docker labels