diff --git a/fix-duplicate-mail-ids b/fix-duplicate-mail-ids
old mode 100644
new mode 100755
diff --git a/fix-maildir-mbsync-duplicate-uid b/fix-maildir-mbsync-duplicate-uid
new file mode 100755
index 0000000..c5dc935
--- /dev/null
+++ b/fix-maildir-mbsync-duplicate-uid
@@ -0,0 +1,27 @@
+#!/bin/sh
+# Nico Schottelius, 2024-05-08
+# Can also be run in a loop with:
+# for uid in $(find . | grep -o 'U=.*:' | sort | uniq -d | sed -e 's/U=//' -e 's/:$//') ; do fix-maildir-mbsync-duplicate-uid $uid; done
+
+if [ $# -ne 1 ]; then
+    echo $0 UID
+    echo "Remove the UID from the newer message"
+fi
+
+MAIL_UID=$1
+
+i=0
+
+for mail in $(ls *U=${MAIL_UID}:*); do
+    i=$((i+1))
+    # Do not rename the first one
+    if [ $i = 1 ]; then
+        continue
+    fi
+
+    # Rename all others
+    new_name=$(echo $mail | sed 's/,U=.*//')
+
+    echo "Renaming $mail to $new_name"
+    mv $mail $new_name
+done