diff --git a/src/main/java/org/alfresco/repo/jscript/ScriptNode.java b/src/main/java/org/alfresco/repo/jscript/ScriptNode.java
index 4691511f32..adfa5a53ce 100644
--- a/src/main/java/org/alfresco/repo/jscript/ScriptNode.java
+++ b/src/main/java/org/alfresco/repo/jscript/ScriptNode.java
@@ -3950,6 +3950,20 @@ public class ScriptNode implements Scopeable, NamespacePrefixResolverProvider
             // update cached variables after putContent()
             updateContentData(true);
         }
+
+        /**
+         * Set the content stream from another content object.
+         *
+         * @param content       ScriptContent to set
+         * @param applyMimetype If true, apply the mimetype from the Content object, else leave the original mimetype
+         * @param guessEncoding If true, guess the encoding from the underlying input stream, else use encoding set in
+         *                      the Content object as supplied.
+         */
+        @Deprecated
+        public void write(Content content, boolean applyMimetype, boolean guessEncoding)
+        {
+            write(content, applyMimetype, guessEncoding, null);
+        }
         
         /**
          * Set the content stream from another content object.
@@ -3958,15 +3972,23 @@ public class ScriptNode implements Scopeable, NamespacePrefixResolverProvider
          * @param applyMimetype If true, apply the mimetype from the Content object, else leave the original mimetype
          * @param guessEncoding If true, guess the encoding from the underlying input stream, else use encoding set in
          *                      the Content object as supplied.
+         * @param fileName      The filename for the attachment.
          */
-        public void write(Content content, boolean applyMimetype, boolean guessEncoding)
+        public void write(Content content, boolean applyMimetype, boolean guessEncoding, String fileName)
         {
             ContentService contentService = services.getContentService();
             ContentWriter writer = contentService.getWriter(nodeRef, this.property, true);
             InputStream is = null;
             if (applyMimetype)
             {
-                writer.setMimetype(content.getMimetype().toLowerCase());
+                if (fileName != null && !fileName.isEmpty())
+                {
+                    writer.setMimetype(services.getMimetypeService().guessMimetype(fileName));
+                } 
+                else 
+                {
+                    writer.setMimetype(content.getMimetype().toLowerCase());
+                }
             }
             if (guessEncoding)
             {
diff --git a/src/test/java/org/alfresco/repo/jscript/ScriptNodeTest.java b/src/test/java/org/alfresco/repo/jscript/ScriptNodeTest.java
index e90b30a1b3..083e42a2a0 100644
--- a/src/test/java/org/alfresco/repo/jscript/ScriptNodeTest.java
+++ b/src/test/java/org/alfresco/repo/jscript/ScriptNodeTest.java
@@ -95,6 +95,7 @@ import org.junit.rules.RuleChain;
 import org.junit.rules.TestName;
 import org.mozilla.javascript.Context;
 import org.mozilla.javascript.ScriptableObject;
+import org.springframework.extensions.surf.util.InputStreamContent;
 
 
 /**
@@ -848,4 +849,44 @@ public class ScriptNodeTest
             fail("Converting multiple property for Activiti script fails with " + e);
         }
     }
+
+    /**
+     *  https://issues.alfresco.com/jira/browse/MNT-19682
+     *  Test that mimetype is correctly set according to the content
+     */
+    @Test
+    public void testWriteContentWithMimetypeAndWithoutFilename()
+    {
+        createTestContent(true);
+        ScriptNode scriptNode = new ScriptNode(testNode, SERVICE_REGISTRY);
+        scriptNode.setScope(getScope());
+
+        ScriptContentData scd = scriptNode.new ScriptContentData(null, ContentModel.PROP_CONTENT);
+
+        InputStream inputStream = getClass().getClassLoader().getResourceAsStream(TEST_CONTENT_MODEL);
+        InputStreamContent inputStreamContent = new InputStreamContent(inputStream, MimetypeMap.MIMETYPE_APPLICATION_PS, "UTF-8");
+
+        scd.write(inputStreamContent, true, false);
+        assertEquals(MimetypeMap.MIMETYPE_APPLICATION_PS, scriptNode.getMimetype());
+    }
+
+    /**
+     *  https://issues.alfresco.com/jira/browse/MNT-19682
+     *  Test that mimetype is correctly set according to the filename
+     */
+    @Test
+    public void testWriteContentWithMimetypeAndFilename()
+    {
+        createTestContent(true);
+        ScriptNode scriptNode = new ScriptNode(testNode, SERVICE_REGISTRY);
+        scriptNode.setScope(getScope());
+
+        ScriptContentData scd = scriptNode.new ScriptContentData(null, ContentModel.PROP_CONTENT);
+
+        InputStream inputStream = getClass().getClassLoader().getResourceAsStream(TEST_CONTENT_MODEL);
+        InputStreamContent inputStreamContent = new InputStreamContent(inputStream, MimetypeMap.MIMETYPE_APPLICATION_PS, "UTF-8");
+
+        scd.write(inputStreamContent, true, false, "test.ai");
+        assertEquals(MimetypeMap.MIMETYPE_APPLICATION_ILLUSTRATOR, scriptNode.getMimetype());
+    }
 }