diff --git a/Makefile b/Makefile
index d4ff4a1..9f62ede 100644
--- a/Makefile
+++ b/Makefile
@@ -30,6 +30,7 @@ t: test
 	mkdir $@
 	curl -Ss https://course.ccs.neu.edu/cs3700sp20/archive/tcp-sim.tgz | tar xzf - -C $@
 	sed -i '/.usr.bin.sudo/d' .netsim/netsim
+	cd /usr/include; h2ph -d $(HOME)/perl5/lib/perl5/ -a sys/syscall.h
 
 netsim-shell: .netsim
 	./scripts/create-net-ns.sh
diff --git a/scripts/create-net-ns.sh b/scripts/create-net-ns.sh
index b54edea..a304a9b 100755
--- a/scripts/create-net-ns.sh
+++ b/scripts/create-net-ns.sh
@@ -6,5 +6,7 @@ cd $(dirname $DIR)
 sudo unshare -n capsh --caps="cap_net_admin+eip cap_setpcap,cap_setuid,cap_setgid+ep" --keep=1 \
     --user=$USER --addamb=cap_net_admin \
     -- -c "export PATH=$PWD/.netsim:\$PATH; export HOME=$PWD; /usr/bin/ip link set lo up; netsim; \
+           export PERL5LIB=\"/home/$USER/perl5/lib/perl5\${PERL5LIB:+:\${PERL5LIB}}\" \
+           export PERL_LOCAL_LIB_ROOT=\"/home/$USER/perl5\${PERL_LOCAL_LIB_ROOT:+:\${PERL_LOCAL_LIB_ROOT}}\" \
            tc qdisc show dev lo; /bin/bash --init-file <(echo unset HISTFILE)"
 true