diff --git a/etc/chasquid/hooks/post-data b/etc/chasquid/hooks/post-data
index ae24315..87fa507 100755
--- a/etc/chasquid/hooks/post-data
+++ b/etc/chasquid/hooks/post-data
@@ -80,7 +80,7 @@ fi
 #  - certs/$DOMAIN/dkim_privkey.pem file exists.
 #
 # Note this has not been thoroughly tested, so might need further adjustments.
-if [ "$AUTH_AS" != "" ] && command -v dkimsign; then
+if [ "$AUTH_AS" != "" ] && command -v dkimsign >/dev/null; then
 	DOMAIN=$( echo "$MAIL_FROM" | cut -d '@' -f 2 )
 	if [ -f "domains/$DOMAIN/dkim_selector" ] \
 			&& [ -f "certs/$DOMAIN/dkim_privkey.pem" ]; then