diff --git a/source/test-java/org/alfresco/repo/imap/ImapMessageTest.java b/source/test-java/org/alfresco/repo/imap/ImapMessageTest.java
index f1d4ecd734..415d391c68 100644
--- a/source/test-java/org/alfresco/repo/imap/ImapMessageTest.java
+++ b/source/test-java/org/alfresco/repo/imap/ImapMessageTest.java
@@ -311,7 +311,9 @@ public class ImapMessageTest extends TestCase
         NodeRef contentNode = findNode(companyHomePathInStore + TEST_FILE);
         UserTransaction txn = transactionService.getUserTransaction();
         txn.begin();
-        fileFolderService.rename(contentNode, "testtesttesttesttesttesttesttesttesttest");
+        // modified the new name as the BASE64Decoder may not throw the IOException
+        // see MNT-12995
+        fileFolderService.rename(contentNode, "testtesttesttesttesttesttesttesttesttest1");
         txn.commit();
 
         // Read second message part