diff --git a/cdist/conf/type/__apt_mark/explorer/apt_version b/cdist/conf/type/__apt_mark/explorer/apt_version
old mode 100644
new mode 100755
index 32a0a58f..7bb90cc2
--- a/cdist/conf/type/__apt_mark/explorer/apt_version
+++ b/cdist/conf/type/__apt_mark/explorer/apt_version
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/sh -e
 #
 # 2016 Ander Punnar (cdist at kvlt.ee)
 #
@@ -26,6 +26,6 @@ apt_version_is=$(dpkg-query --show --showformat '${Version}' apt)
 
 apt_version_should=0.8.14.2
 
-dpkg --compare-versions $apt_version_should le $apt_version_is \
+dpkg --compare-versions "$apt_version_should" le "$apt_version_is" \
     && echo 0 \
     || echo 1
diff --git a/cdist/conf/type/__apt_mark/explorer/package_installed b/cdist/conf/type/__apt_mark/explorer/package_installed
old mode 100644
new mode 100755
index c78ac3a9..0b072cbc
--- a/cdist/conf/type/__apt_mark/explorer/package_installed
+++ b/cdist/conf/type/__apt_mark/explorer/package_installed
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/sh -e
 #
 # 2016 Ander Punnar (cdist at kvlt.ee)
 #
@@ -24,7 +24,7 @@ else
     name="$__object_id"
 fi
 
-dpkg-query --show --showformat '${Status}' $name 2>/dev/null \
-    | grep -q 'ok installed' \
+dpkg-query --show --showformat '${Status}' "$name" 2>/dev/null \
+    | grep -Fq 'ok installed' \
     && echo 0 \
     || echo 1
diff --git a/cdist/conf/type/__apt_mark/explorer/state b/cdist/conf/type/__apt_mark/explorer/state
old mode 100644
new mode 100755
index 3b70003a..b7fe08fa
--- a/cdist/conf/type/__apt_mark/explorer/state
+++ b/cdist/conf/type/__apt_mark/explorer/state
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/sh -e
 #
 # 2016 Ander Punnar (cdist at kvlt.ee)
 #
@@ -24,4 +24,4 @@ else
     name="$__object_id"
 fi
 
-apt-mark showhold | grep -q $name && echo hold || echo unhold
+apt-mark showhold | grep -Fq "$name" && echo hold || echo unhold