diff --git a/regress/Makefile b/regress/Makefile
index 2eb2e3181..636858662 100644
--- a/regress/Makefile
+++ b/regress/Makefile
@@ -81,7 +81,7 @@ CLEANFILES=	t2.out t3.out t6.out1 t6.out2 t7.out t7.out.pub copy.1 copy.2 \
 		putty.rsa2 sshd_proxy_orig ssh_proxy_bak \
 		key.rsa-* key.dsa-* key.ecdsa-* \
 		authorized_principals_${USER} expect actual ready \
-		sshd_proxy.* authorized_keys_${USER}.*
+		sshd_proxy.* authorized_keys_${USER}.* modpipe
 
 
 # Enable all malloc(3) randomisations and checks
@@ -143,15 +143,15 @@ t9: $(OBJ)/t9.out
 	test "${TEST_SSH_ECC}" != yes || \
 	${TEST_SSH_SSHKEYGEN} -Bf $(OBJ)/t9.out > /dev/null
 
-modpipe: modpipe.c
-
-t-exec:	modpipe ${LTESTS:=.sh}
+t-exec:	${LTESTS:=.sh} modpipe
 	@if [ "x$?" = "x" ]; then exit 0; fi; \
 	for TEST in ""$?; do \
 		echo "run test $${TEST}" ... 1>&2; \
 		(env SUDO="${SUDO}" TEST_ENV=${TEST_ENV} sh ${.CURDIR}/test-exec.sh ${.OBJDIR} ${.CURDIR}/$${TEST}) || exit $$?; \
 	done
 
+modpipe: modpipe.c
+
 t-exec-interop:	${INTEROP_TESTS:=.sh}
 	@if [ "x$?" = "x" ]; then exit 0; fi; \
 	for TEST in ""$?; do \
diff --git a/regress/integrity.sh b/regress/integrity.sh
index 23135685c..f6e5c1963 100644
--- a/regress/integrity.sh
+++ b/regress/integrity.sh
@@ -18,6 +18,10 @@ macs="hmac-sha1 hmac-md5 umac-64@openssh.com umac-128@openssh.com
 # sshd-command for proxy (see test-exec.sh)
 cmd="sh ${SRC}/sshd-log-wrapper.sh ${SSHD} ${TEST_SSH_LOGFILE} -i -f $OBJ/sshd_proxy"
 
+jot() {
+	awk 'BEGIN { for (i = $2; i < $2 + $1; i++) { printf "%d\n", i } }'
+}
+set -x
 for m in $macs; do
 	trace "test $tid: mac $m"
 	elen=0
@@ -26,7 +30,8 @@ for m in $macs; do
 	ecnt=0
 	skip=0
 	for off in $(jot $tries $startoffset); do
-		if [ $((skip--)) -gt 0 ]; then
+		skip=$((skip - 1))
+		if [ $skip -gt 0 ]; then
 			# avoid modifying the high bytes of the length
 			continue
 		fi