diff --git a/source/java/org/alfresco/repo/jscript/ScriptNode.java b/source/java/org/alfresco/repo/jscript/ScriptNode.java
index ff402028a8..b3197ce0f2 100644
--- a/source/java/org/alfresco/repo/jscript/ScriptNode.java
+++ b/source/java/org/alfresco/repo/jscript/ScriptNode.java
@@ -3923,7 +3923,7 @@ public class ScriptNode implements Scopeable, NamespacePrefixResolverProvider
             InputStream is = null;
             if (applyMimetype)
             {
-                writer.setMimetype(content.getMimetype());
+                writer.setMimetype(content.getMimetype().toLowerCase());
             }
             if (guessEncoding)
             {