diff --git a/missions/processes/03_pstree_kill/i18n/en.po b/missions/processes/03_pstree_kill/i18n/en.po
index 954e21fa..85344475 100644
--- a/missions/processes/03_pstree_kill/i18n/en.po
+++ b/missions/processes/03_pstree_kill/i18n/en.po
@@ -31,6 +31,12 @@ msgstr  "Did you melt some of the snowflakes?"
 msgid   "Did you remove some of the fairy's spells?"
 msgstr  "Did you remove some of the fairy's spells?"
 
+#, sh-format
+msgid   "The command 'pstree' is required for mission $MISSION_NAME.\n"
+        "(Debian / Ubuntu: install package 'psmisc')"
+msgstr  "The command 'pstree' is required for mission $MISSION_NAME.\n"
+        "(Debian / Ubuntu: install package 'psmisc')"
+
 msgid   "There still is some coal in the cellar!"
 msgstr  "There still is some coal in the cellar!"
 
diff --git a/missions/processes/03_pstree_kill/i18n/fr.po b/missions/processes/03_pstree_kill/i18n/fr.po
index c8c2a954..56c0bd63 100644
--- a/missions/processes/03_pstree_kill/i18n/fr.po
+++ b/missions/processes/03_pstree_kill/i18n/fr.po
@@ -30,6 +30,12 @@ msgstr  "Est-ce que vous avez fait fondre des flocons ?"
 msgid   "Did you remove some of the fairy's spells?"
 msgstr  "Est-ce que vous avez supprimé un sortilège de la fée ?"
 
+#, sh-format
+msgid   "The command 'pstree' is required for mission $MISSION_NAME.\n"
+        "(Debian / Ubuntu: install package 'psmisc')"
+msgstr  "La command 'pstree' est nécesaire pour la mission $MISSION_NAME.\n"
+        "(Debian / Ubuntu : installez le paquet 'psmisc')"
+
 msgid   "There still is some coal in the cellar!"
 msgstr  "Il reste des morceaux de charbon dans la cave !"
 
diff --git a/missions/processes/03_pstree_kill/i18n/template.pot b/missions/processes/03_pstree_kill/i18n/template.pot
index f53cacbf..317cda98 100644
--- a/missions/processes/03_pstree_kill/i18n/template.pot
+++ b/missions/processes/03_pstree_kill/i18n/template.pot
@@ -30,6 +30,11 @@ msgstr  ""
 msgid   "Did you remove some of the fairy's spells?"
 msgstr  ""
 
+#, sh-format
+msgid   "The command 'pstree' is required for mission $MISSION_NAME.\n"
+        "(Debian / Ubuntu: install package 'psmisc')"
+msgstr  ""
+
 msgid   "There still is some coal in the cellar!"
 msgstr  ""
 
diff --git a/missions/processes/03_pstree_kill/init.sh b/missions/processes/03_pstree_kill/init.sh
index efb740b7..25317e66 100644
--- a/missions/processes/03_pstree_kill/init.sh
+++ b/missions/processes/03_pstree_kill/init.sh
@@ -33,6 +33,14 @@ _mission_init() {
     mission_source "$MISSION_DIR/deps.sh" || return 1
   fi
 
+  if ! command -v pstree >/dev/null
+  then
+    echo "$(eval_gettext "The command 'pstree' is required for mission \$MISSION_NAME.
+(Debian / Ubuntu: install package 'psmisc')")" >&2
+    return 1
+
+  fi
+
   if [ -n "$CC" ]
   then
     (