diff --git a/api/api-rules/violation_exceptions.list b/api/api-rules/violation_exceptions.list
index ebb0bd6f40f..0e6a3e73057 100644
--- a/api/api-rules/violation_exceptions.list
+++ b/api/api-rules/violation_exceptions.list
@@ -90,7 +90,6 @@ API rule violation: list_type_missing,k8s.io/api/core/v1,EphemeralContainerCommo
 API rule violation: list_type_missing,k8s.io/api/core/v1,EphemeralContainerCommon,Command
 API rule violation: list_type_missing,k8s.io/api/core/v1,EphemeralContainerCommon,Env
 API rule violation: list_type_missing,k8s.io/api/core/v1,EphemeralContainerCommon,EnvFrom
-API rule violation: list_type_missing,k8s.io/api/core/v1,EphemeralContainerCommon,Ports
 API rule violation: list_type_missing,k8s.io/api/core/v1,EphemeralContainerCommon,VolumeDevices
 API rule violation: list_type_missing,k8s.io/api/core/v1,EphemeralContainerCommon,VolumeMounts
 API rule violation: list_type_missing,k8s.io/api/core/v1,ExecAction,Command
diff --git a/pkg/apis/core/types_test.go b/pkg/apis/core/types_test.go
new file mode 100644
index 00000000000..813036d13a0
--- /dev/null
+++ b/pkg/apis/core/types_test.go
@@ -0,0 +1,41 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package core
+
+import (
+	"reflect"
+	"testing"
+)
+
+// TestEphemeralContainer ensures that the tags of Container and EphemeralContainerCommon are kept in sync.
+func TestEphemeralContainer(t *testing.T) {
+	ephemeralType := reflect.TypeOf(EphemeralContainerCommon{})
+	containerType := reflect.TypeOf(Container{})
+
+	ephemeralFields := ephemeralType.NumField()
+	containerFields := containerType.NumField()
+	if containerFields != ephemeralFields {
+		t.Fatalf("%v has %d fields, %v has %d fields", ephemeralType, ephemeralFields, containerType, containerFields)
+	}
+	for i := 0; i < ephemeralFields; i++ {
+		ephemeralField := ephemeralType.Field(i)
+		containerField := containerType.Field(i)
+		if !reflect.DeepEqual(ephemeralField, containerField) {
+			t.Errorf("field %v differs:\n\t%#v\n\t%#v", ephemeralField.Name, ephemeralField, containerField)
+		}
+	}
+}
diff --git a/staging/src/k8s.io/api/core/v1/types.go b/staging/src/k8s.io/api/core/v1/types.go
index eece7073612..c5325d71b21 100644
--- a/staging/src/k8s.io/api/core/v1/types.go
+++ b/staging/src/k8s.io/api/core/v1/types.go
@@ -3475,7 +3475,13 @@ type EphemeralContainerCommon struct {
 	// +optional
 	WorkingDir string `json:"workingDir,omitempty" protobuf:"bytes,5,opt,name=workingDir"`
 	// Ports are not allowed for ephemeral containers.
-	Ports []ContainerPort `json:"ports,omitempty" protobuf:"bytes,6,rep,name=ports"`
+	// +optional
+	// +patchMergeKey=containerPort
+	// +patchStrategy=merge
+	// +listType=map
+	// +listMapKey=containerPort
+	// +listMapKey=protocol
+	Ports []ContainerPort `json:"ports,omitempty" patchStrategy:"merge" patchMergeKey:"containerPort" protobuf:"bytes,6,rep,name=ports"`
 	// List of sources to populate environment variables in the container.
 	// The keys defined within a source must be a C_IDENTIFIER. All invalid keys
 	// will be reported as an event when the container is starting. When a key exists in multiple
diff --git a/staging/src/k8s.io/api/core/v1/types_test.go b/staging/src/k8s.io/api/core/v1/types_test.go
index 6c602403bef..923c3b868b5 100644
--- a/staging/src/k8s.io/api/core/v1/types_test.go
+++ b/staging/src/k8s.io/api/core/v1/types_test.go
@@ -39,3 +39,22 @@ func Test_ServiceSpecRemovedFieldProtobufNumberReservation(t *testing.T) {
 		}
 	}
 }
+
+// TestEphemeralContainer ensures that the tags of Container and EphemeralContainerCommon are kept in sync.
+func TestEphemeralContainer(t *testing.T) {
+	ephemeralType := reflect.TypeOf(EphemeralContainerCommon{})
+	containerType := reflect.TypeOf(Container{})
+
+	ephemeralFields := ephemeralType.NumField()
+	containerFields := containerType.NumField()
+	if containerFields != ephemeralFields {
+		t.Fatalf("%v has %d fields, %v has %d fields", ephemeralType, ephemeralFields, containerType, containerFields)
+	}
+	for i := 0; i < ephemeralFields; i++ {
+		ephemeralField := ephemeralType.Field(i)
+		containerField := containerType.Field(i)
+		if !reflect.DeepEqual(ephemeralField, containerField) {
+			t.Errorf("field %v differs:\n\t%#v\n\t%#v", ephemeralField.Name, ephemeralField, containerField)
+		}
+	}
+}