diff --git a/container_files/bin/start.sh b/container_files/bin/start.sh
index 581a7cd..7db3e12 100755
--- a/container_files/bin/start.sh
+++ b/container_files/bin/start.sh
@@ -16,10 +16,9 @@ if [ -e "/tmp/firsttimerunning" ]; then
     fi
 
     echo "Setting DataDir: $MYSQL_DATADIR" >> $log
-    sed -e "s=\${MYSQL_DATADIR}=$MYSQL_DATADIR=" < /etc/my.cnf > /etc/my.cnf
-
-    echo "/etc/my.cnf is:"
-    cat /etc/my.cnf
+    sed -e "s=\${MYSQL_DATADIR}=$MYSQL_DATADIR=" < /etc/my.cnf > /etc/my.cnf.new
+    rm /etc/my.cnf >> $log
+    mv /etc/my.cnf.new /etc/my.cnf >> $log
 
     if [[ $CREATE_NEW_DATABASE == 1 || ($CREATE_NEW_DATABASE == if_needed && ( ! -d $MYSQL_DATADIR || -z $(ls -A $MYSQL_DATADIR) ) ) ]]; then