diff --git a/graylog2-server/src/main/java/org/graylog2/rest/resources/system/inputs/InputsResource.java b/graylog2-server/src/main/java/org/graylog2/rest/resources/system/inputs/InputsResource.java
index d499d17896f8..715aeff737eb 100644
--- a/graylog2-server/src/main/java/org/graylog2/rest/resources/system/inputs/InputsResource.java
+++ b/graylog2-server/src/main/java/org/graylog2/rest/resources/system/inputs/InputsResource.java
@@ -176,7 +176,7 @@ public Response update(@ApiParam(name = "JSON body", required = true) @Valid @No
 
         final Input input = inputService.find(inputId);
 
-        final Map<String, Object> mergedInput = inputService.getMessageInput(input).asMap();
+        final Map<String, Object> mergedInput = input.getFields();
         final MessageInput messageInput = messageInputFactory.create(lr, getCurrentUser().getName(), lr.node());
 
         messageInput.checkConfiguration();