diff --git a/debian/control b/debian/control
index e812ff9..2d641c9 100644
--- a/debian/control
+++ b/debian/control
@@ -7,8 +7,7 @@ Standards-Version: 3.8.0
 
 Package: evomaintenance
 Architecture: all
-Depends: postgresql-client, sudo
+Depends: coreutils, sudo, sed, hostname, postfix, git, postgresql-client
 Description: script for Evolix maintenance
  This package contains the script evomaintenance.sh
  which sends a mail for each intervention on a Pack Evolix server.
-
diff --git a/evomaintenance.sh b/evomaintenance.sh
index cee64b3..234f24b 100755
--- a/evomaintenance.sh
+++ b/evomaintenance.sh
@@ -199,8 +199,8 @@ hook_db() {
     if [ "${VERBOSE}" = "1" ]; then
         printf "\n********** DB query **************\n%s\n***********************************\n" "${PG_QUERY}"
     fi
-    if [ "${DRY_RUN}" != "1" ]; then
-        echo "${PG_QUERY}" | psql "${PGDB}" "${PGTABLE}" -h "${PGHOST}"
+    if [ "${DRY_RUN}" != "1" ] && [ -x "${PSQL_BIN}" ]; then
+        echo "${PG_QUERY}" | ${PSQL_BIN} "${PGDB}" "${PGTABLE}" -h "${PGHOST}"
     fi
 }
 
@@ -256,7 +256,7 @@ hook_mail() {
     if [ "${VERBOSE}" = "1" ]; then
         printf "\n********** Mail *******************\n%s\n***********************************\n" "${MAIL_CONTENT}"
     fi
-    if [ "${DRY_RUN}" != "1" ]; then
+    if [ "${DRY_RUN}" != "1" ] && [ -x "${SENDMAIL_BIN}" ]; then
         echo "${MAIL_CONTENT}" | ${SENDMAIL_BIN} -oi -t -f "${FROM}"
     fi
 }
@@ -396,9 +396,21 @@ PATH=${PATH}:/usr/sbin
 
 SENDMAIL_BIN=$(command -v sendmail)
 readonly SENDMAIL_BIN
+if [ -z "${SENDMAIL_BIN}" ]; then
+    echo "No \`sendmail' command has been found, can't send mail." 2>&1
+fi
 
 GIT_BIN=$(command -v git)
 readonly GIT_BIN
+if [ -z "${GIT_BIN}" ]; then
+    echo "No \`git' command has been found, can't commit changes" 2>&1
+fi
+
+PSQL_BIN=$(command -v psql)
+readonly PSQL_BIN
+if [ -z "${PSQL_BIN}" ]; then
+    echo "No \`psql' command has been found, can't save to the database." 2>&1
+fi
 
 GIT_REPOSITORIES="/etc /etc/bind"