diff --git a/appdir-lint.sh b/appdir-lint.sh
old mode 100644
new mode 100755
index fac57a35..b4b01403
--- a/appdir-lint.sh
+++ b/appdir-lint.sh
@@ -17,10 +17,15 @@ warn () {
   echo "WARNING: $1"
 }
 
-which desktop-file-validate >/dev/null
-if [ ! $? -eq 0 ] ; then
-  fatal "desktop-file-validate is missing, please install it"
-fi
+depends () {
+  if ! which "$1" >/dev/null; then
+    fatal "$1 is missing, please install it"
+  fi
+}
+
+depends desktop-file-validate
+depends mimetype
+depends appstreamcli
 
 if [ ! -e "${HERE}/excludelist" ] ; then
   fatal "excludelist missing, please install it"
@@ -130,11 +135,7 @@ fi
 if [ -z "$APPDATA" ] ; then
   warn 'No appdata file present. Please provide one in the AppImage as per the instructions on https://www.freedesktop.org/software/appstream/docs/chap-Quickstart.html#sect-Quickstart-DesktopApps'
 else
-  if [ ! -z $(which appstreamcli) ] ; then
-    appstreamcli validate-tree "${APPDIR}"
-  else
-    echo "Skipping AppStream validation since appstreamcli is not on the \$PATH"
-  fi
+  appstreamcli validate-tree "${APPDIR}"
 fi