diff --git a/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/action/PostDataAction.java b/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/action/PostDataAction.java
index 9253467b1a7..9ba1bf574db 100644
--- a/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/action/PostDataAction.java
+++ b/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/action/PostDataAction.java
@@ -178,7 +178,7 @@ public class PostDataAction extends Action<PostDataAction.Request, PostDataActio
             dataDescription = in.readOptionalWriteable(DataDescription::new);
             content = in.readBytesReference();
             if (in.readBoolean()) {
-                xContentType = XContentType.readFrom(in);
+                xContentType = in.readEnum(XContentType.class);
             }
         }
 
@@ -192,7 +192,7 @@ public class PostDataAction extends Action<PostDataAction.Request, PostDataActio
             boolean hasXContentType = xContentType != null;
             out.writeBoolean(hasXContentType);
             if (hasXContentType) {
-                xContentType.writeTo(out);
+                out.writeEnum(xContentType);
             }
         }
 
diff --git a/plugin/core/src/main/java/org/elasticsearch/xpack/core/monitoring/action/MonitoringBulkDoc.java b/plugin/core/src/main/java/org/elasticsearch/xpack/core/monitoring/action/MonitoringBulkDoc.java
index ab243d62e0a..9ddc2c6d9ec 100644
--- a/plugin/core/src/main/java/org/elasticsearch/xpack/core/monitoring/action/MonitoringBulkDoc.java
+++ b/plugin/core/src/main/java/org/elasticsearch/xpack/core/monitoring/action/MonitoringBulkDoc.java
@@ -70,7 +70,7 @@ public class MonitoringBulkDoc implements Writeable {
         final String type = in.readOptionalString();
         final String id = in.readOptionalString();
         final BytesReference source = in.readBytesReference();
-        final XContentType xContentType = (source != BytesArray.EMPTY) ? XContentType.readFrom(in) : XContentType.JSON;
+        final XContentType xContentType = (source != BytesArray.EMPTY) ? in.readEnum(XContentType.class) : XContentType.JSON;
 
         long interval = 0L;
         if (in.getVersion().onOrAfter(Version.V_6_0_0_rc1)) {
@@ -95,7 +95,7 @@ public class MonitoringBulkDoc implements Writeable {
         out.writeOptionalString(id);
         out.writeBytesReference(source);
         if (source != BytesArray.EMPTY) {
-            xContentType.writeTo(out);
+            out.writeEnum(xContentType);
         }
         if (out.getVersion().onOrAfter(Version.V_6_0_0_rc1)) {
             out.writeVLong(intervalMillis);
diff --git a/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/support/xcontent/WatcherXContentParser.java b/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/support/xcontent/WatcherXContentParser.java
index 09b7d0bf8de..6b97512c237 100644
--- a/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/support/xcontent/WatcherXContentParser.java
+++ b/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/support/xcontent/WatcherXContentParser.java
@@ -293,7 +293,7 @@ public class WatcherXContentParser implements XContentParser {
     }
 
     @Override
-    public void close() throws ElasticsearchException {
+    public void close() throws IOException {
         parser.close();
     }
 
diff --git a/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/support/xcontent/XContentSource.java b/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/support/xcontent/XContentSource.java
index 3712478bc32..92ab8752fec 100644
--- a/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/support/xcontent/XContentSource.java
+++ b/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/support/xcontent/XContentSource.java
@@ -112,12 +112,12 @@ public class XContentSource implements ToXContent {
     }
 
     public static XContentSource readFrom(StreamInput in) throws IOException {
-        return new XContentSource(in.readBytesReference(), XContentType.readFrom(in));
+        return new XContentSource(in.readBytesReference(), in.readEnum(XContentType.class));
     }
 
     public static void writeTo(XContentSource source, StreamOutput out) throws IOException {
         out.writeBytesReference(source.bytes);
-        source.contentType.writeTo(out);
+        out.writeEnum(source.contentType);
     }
 
     private Object data() {
diff --git a/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/transport/actions/execute/ExecuteWatchRequest.java b/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/transport/actions/execute/ExecuteWatchRequest.java
index ab68ef2fd84..bece3e5a6f5 100644
--- a/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/transport/actions/execute/ExecuteWatchRequest.java
+++ b/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/transport/actions/execute/ExecuteWatchRequest.java
@@ -69,7 +69,7 @@ public class ExecuteWatchRequest extends ActionRequest {
         }
         if (in.readBoolean()) {
             watchSource = in.readBytesReference();
-            xContentType = XContentType.readFrom(in);
+            xContentType = in.readEnum(XContentType.class);
         }
         debug = in.readBoolean();
     }
@@ -96,7 +96,7 @@ public class ExecuteWatchRequest extends ActionRequest {
         out.writeBoolean(watchSource != null);
         if (watchSource != null) {
             out.writeBytesReference(watchSource);
-            xContentType.writeTo(out);
+            out.writeEnum(xContentType);
         }
         out.writeBoolean(debug);
     }
diff --git a/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/transport/actions/put/PutWatchRequest.java b/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/transport/actions/put/PutWatchRequest.java
index 3c3d80871b1..1985602d4df 100644
--- a/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/transport/actions/put/PutWatchRequest.java
+++ b/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/transport/actions/put/PutWatchRequest.java
@@ -45,7 +45,7 @@ public class PutWatchRequest extends ActionRequest {
         id = in.readString();
         source = in.readBytesReference();
         active = in.readBoolean();
-        xContentType = XContentType.readFrom(in);
+        xContentType = in.readEnum(XContentType.class);
         version = in.readZLong();
     }
 
@@ -55,7 +55,7 @@ public class PutWatchRequest extends ActionRequest {
         out.writeString(id);
         out.writeBytesReference(source);
         out.writeBoolean(active);
-        xContentType.writeTo(out);
+        out.writeEnum(xContentType);
         out.writeZLong(version);
     }