Index: flume-ng/src/test/resources/embedded.xml
===================================================================
--- flume-ng/src/test/resources/embedded.xml	(revision 1483493)
+++ flume-ng/src/test/resources/embedded.xml	(working copy)
@@ -4,6 +4,10 @@
     <Flume name="eventLogger" suppressExceptions="false" compress="true" type="embedded">
       <Property name="channels">primary</Property>
       <Property name="channels.primary.type">memory</Property>
+      <Property name="sources.log4j-source.interceptors">environment_interceptor</Property>
+      <Property name="sources.log4j-source.interceptors.environment_interceptor.type">static</Property>
+      <Property name="sources.log4j-source.interceptors.environment_interceptor.key">environment</Property>
+      <Property name="sources.log4j-source.interceptors.environment_interceptor.value">local</Property>
       <Property name="sinks">agent1 agent2</Property>
       <Property name="sinks.agent1.channel">primary</Property>
       <Property name="sinks.agent1.type">avro</Property>
Index: flume-ng/src/test/java/org/apache/logging/log4j/flume/appender/FlumeEmbeddedAppenderTest.java
===================================================================
--- flume-ng/src/test/java/org/apache/logging/log4j/flume/appender/FlumeEmbeddedAppenderTest.java	(revision 1483493)
+++ flume-ng/src/test/java/org/apache/logging/log4j/flume/appender/FlumeEmbeddedAppenderTest.java	(working copy)
@@ -193,6 +193,18 @@
     }
 
     @Test
+    public void testHeaderAddedByInterceptor() throws InterruptedException, IOException {
+
+        final StructuredDataMessage msg = new StructuredDataMessage("Test", "Test Log4j", "Test");
+        EventLogger.logEvent(msg);
+
+        final Event event = primary.poll();
+        Assert.assertNotNull(event);
+        String environmentHeader = event.getHeaders().get("environment");
+        Assert.assertEquals("local", environmentHeader);
+    }
+
+    @Test
     public void testPerformance() throws Exception {
         long start = System.currentTimeMillis();
         int count = 10000;
Index: flume-ng/src/main/java/org/apache/logging/log4j/flume/appender/FlumeEmbeddedManager.java
===================================================================
--- flume-ng/src/main/java/org/apache/logging/log4j/flume/appender/FlumeEmbeddedManager.java	(revision 1483493)
+++ flume-ng/src/main/java/org/apache/logging/log4j/flume/appender/FlumeEmbeddedManager.java	(working copy)
@@ -274,7 +274,8 @@
                         throw new ConfigurationException(msg);
                     }
 
-                    if (upperKey.startsWith("SOURCES.")) {
+                    // Prohibit setting the sources as they are set above but allow interceptors to be set
+                    if (upperKey.startsWith("SOURCES.") && !upperKey.startsWith("SOURCES.LOG4J-SOURCE.INTERCEPTORS")) {
                         final String msg = "Specification of Sources is not allowed in Flume Appender: " + key;
                         LOGGER.error(msg);
                         throw new ConfigurationException(msg);
Index: src/site/xdoc/manual/appenders.xml
===================================================================
--- src/site/xdoc/manual/appenders.xml	(revision 1483493)
+++ src/site/xdoc/manual/appenders.xml	(working copy)
@@ -878,7 +878,8 @@
               <td>Property[]</td>
               <td><p>One or more Property elements that are used to configure the Flume Agent. The properties must be
                 configured without the agent name (the appender name is used for this) and no sources can be
-                configured. All other Flume configuration properties are allowed. Specifying both Agent and Property
+                configured. Interceptors can be specified for the source using "sources.log4j-source.interceptors". 
+                All other Flume configuration properties are allowed. Specifying both Agent and Property
                 elements will result in an error.</p>
                 <p>When used to configure in Persistent mode the valid properties are:
                   <ol>