diff --git a/Scripts/sql-update-1.3.11_to_1.3.12-mysql.sh b/Scripts/sql-update-1.3.11_to_1.3.12-mysql.sh
new file mode 100644
index 000000000..50543a7f1
--- /dev/null
+++ b/Scripts/sql-update-1.3.11_to_1.3.12-mysql.sh
@@ -0,0 +1,36 @@
+#!/bin/bash
+# converting c_content to text is not needed on mysql as it is already big enough (mediumtext)
+
+# this script only works with MySQL
+
+defaultusername=$USER
+defaulthostname=localhost
+defaultdatabase=$USER
+
+read -p "Username ($defaultusername): " username
+read -p "Hostname ($defaulthostname): " hostname
+read -p "Database ($defaultdatabase): " database
+
+if [ -z "$username" ]
+then
+  username=$defaultusername
+fi
+
+if [ -z "$hostname" ]
+then
+  hostname=$defaulthostname
+fi
+
+if [ -z "$database" ]
+then
+  database=$defaultdatabase
+ fi
+
+SESSIONTBL=$(su - sogo -c "defaults read sogod OCSSessionsFolderURL" | awk -F/ '{print $NF}')
+if [ -z "$SESSIONTBL" ]; then
+  echo "Failed to obtain session table name" >&2
+  exit 1
+fi
+
+echo "Fix primary key for the sogo_sessions table"
+mysql -p -s -u $username -h $hostname $database -e "ALTER TABLE $SESSIONTBL ADD PRIMARY KEY (c_id);"
diff --git a/Scripts/sql-update-1.3.11_to_1.3.12.sh b/Scripts/sql-update-1.3.11_to_1.3.12.sh
index 17b8c0405..8cf6839e8 100755
--- a/Scripts/sql-update-1.3.11_to_1.3.12.sh
+++ b/Scripts/sql-update-1.3.11_to_1.3.12.sh
@@ -34,6 +34,7 @@ function convVCtoText() {
     IFS="$oldIFS"
 }
 
+echo "Step 1 - Converting c_content from VARCHAR to TEXT in table sogo_folder_info" >&2
 tables=`psql -t -U $username -h $hostname $database -c "select split_part(c_location, '/', 5) from $indextable;"`
 
 for table in $tables;
@@ -42,3 +43,13 @@ do
 done
 
 echo "$sqlscript" | psql -q -e -U $username -h $hostname $database
+
+echo "Step 2 - Fix primary key for the sogo_sessions table" >&2
+SESSIONTBL=$(su - sogo -c "defaults read sogod OCSSessionsFolderURL" | awk -F/ '{print $NF}')
+if [ -z "$SESSIONTBL" ]; then
+  echo "Failed to obtain session table name" >&2
+  exit 1
+fi
+
+psql -e -U $username -h $hostname $database -c "ALTER TABLE $SESSIONTBL ADD PRIMARY KEY (c_id);"
+