diff --git a/metapackage/postinst b/metapackage/postinst
index 686b989..22c9be1 100644
--- a/metapackage/postinst
+++ b/metapackage/postinst
@@ -1,3 +1,4 @@
+#!/bin/sh
 wget -O ~/.gdbinit-gef.py -q http://gef.blah.cat/py
 echo source ~/.gdbinit-gef.py >> ~/.gdbinit
 
diff --git a/metapackage/preinst b/metapackage/preinst
index 65c8c34..c3b217f 100644
--- a/metapackage/preinst
+++ b/metapackage/preinst
@@ -1,3 +1,4 @@
+#!/bin/sh
 cat << 'EOF' > /etc/apt/sources.list.d/kali-experimental.list
 deb https://http.kali.org/kali kali-experimental main contrib non-free
 EOF