diff --git a/b2-backup.sh b/b2-backup.sh
index 9e32300..d5ea65d 100755
--- a/b2-backup.sh
+++ b/b2-backup.sh
@@ -1,7 +1,10 @@
-#!/bin/sh
+#!/bin/bash
+
+set -ue
 
 # Import all account and GPG variables
 source ./b2.cred
+export PASSPHRASE=${GPG_PASSPHRASE}
 
 # Local directory to backup
 LOCAL_DIR="/media/usb0/backup"
@@ -20,3 +23,6 @@ duplicity cleanup --force \
 duplicity collection-status \
           --encrypt-sign-key $GPG_KEY \
           b2://${B2_ACCOUNT}:${B2_KEY}@${B2_BUCKET}
+
+# Unset the GPG passphrase
+unset PASSPHRASE