diff --git a/Installation/arangodb-helper b/Installation/arangodb-helper
index 6c54a5d74a..2e66bc4da8 100644
--- a/Installation/arangodb-helper
+++ b/Installation/arangodb-helper
@@ -69,7 +69,7 @@ ar_exitcode_num_to_string(){
     local found=false
     if [ -f "$file" ]; then
         while IFS=',' read code num _ ; do
-            if [ "$in" == "$num" ]; then
+            if [ "$in" = "$num" ]; then
                 echo $code
                 found=true
                 break
@@ -86,14 +86,14 @@ ar_exitcode_num_to_string(){
 
 ar_exitcode_num_to_message(){
     local in="$1"
-    if [[ $in == "0" ]]; then
+    if [ $in = "0" ]; then
         return
     fi
     local file="$ARANGO_ERROR_CODES_DAT"
     local found=false
     if [ -f $file ]; then
         while IFS=',' read code num message long_message; do
-            if [ "$in" == "$num" ]; then
+            if [ "$in" = "$num" ]; then
                 echo "$message"
                 found=true
                 break
@@ -114,7 +114,7 @@ ar_exitcode_string_to_num(){
     if [ -f $file ]; then
         in="$1"
         while IFS=',' read code num _ ; do
-            if [ "$in" == "$code" ]; then
+            if [ "$in" = "$code" ]; then
                 echo $num
                 found=true
                 break
@@ -131,9 +131,9 @@ ar_exitcode_string_to_num(){
 
 ar_exit_by_num(){
     local code="$1"
-    local str="$(ar_exitcode_num_to_string $code)"
-    local msg="$(ar_exitcode_num_to_message $code)"
     if [ $code -ne 0 ]; then
+        local str="$(ar_exitcode_num_to_string $code)"
+        local msg="$(ar_exitcode_num_to_message $code)"
         echo "FATAL ERROR: $str - $msg" 1>&2
         exit "$code"
     fi
diff --git a/Installation/debian/postinst.in b/Installation/debian/postinst.in
index 9df85d854f..eb9e9c0d51 100755
--- a/Installation/debian/postinst.in
+++ b/Installation/debian/postinst.in
@@ -2,6 +2,7 @@
 set -e
 
 action="$1"
+old_version="$2"
 
 ARANGODB="/usr/sbin/arangod"
 
@@ -9,7 +10,6 @@ ARANGODB="/usr/sbin/arangod"
 . /usr/share/debconf/confmodule
 . /usr/share/arangodb3/arangodb-helper
 
-set +x
 db_get @CPACK_PACKAGE_NAME@/storage_engine
 STORAGE_ENGINE=$RET
 export GLIBCXX_FORCE_NEW=1
@@ -19,10 +19,20 @@ if test -d /var/lib/arangodb3 -a ! -f /usr/sbin/arangod; then
 else
     NEW_INSTALL_EXISTING_DIR=false
 fi
-
 #fill in correct storage engine into arangod.conf
 sed -i /etc/arangodb3/arangod.conf -e "s;storage-engine = auto;storage-engine = $STORAGE_ENGINE;"
 
+if test "@CPACK_SYSTEMD_FOUND@" -eq 1 ; then
+    if deb-systemd-invoke is-active @CPACK_PACKAGE_NAME@.service 2>&1 >/dev/null ; then
+        deb-systemd-invoke stop @CPACK_PACKAGE_NAME@.service >/dev/null \
+            || ar_err "failed to stop arangodb3 service" $?
+    fi
+else
+    if [ -x "/etc/init.d/arangodb3" ]; then
+	    invoke-rc.d arangodb3 stop \
+            || ar_err "failed to stop arangodb3 service" $?
+    fi
+fi
 
 if test "$action" = "configure" -a \
         -z "$2" -a \
@@ -56,7 +66,7 @@ set -e
 if [ $exit_status -eq "$(ar_exitcode_string_to_num EXIT_UPGRADE_REQUIRED)" ]; then
     UPGRADE=true
 else
-    ar_ferr $exit_status
+    ar_exit_by_num $exit_status
 fi