diff --git a/tests.sh b/tests.sh
index 3cabbadbe..a4e8f0639 100755
--- a/tests.sh
+++ b/tests.sh
@@ -9,6 +9,8 @@ PROXY=build/local_prefix/opt/hermit/bin/proxy
 
 for f in $FILES; do echo "check $f..."; HERMIT_ISLE=qemu HERMIT_CPUS=1 HERMIT_KVM=0 HERMIT_VERBOSE=1 timeout --kill-after=5m 5m $PROXY $f || exit 1; done
 
+for f in $FILES; do echo "check $f..."; HERMIT_ISLE=qemu HERMIT_CPUS=2 HERMIT_KVM=0 HERMIT_VERBOSE=1 timeout --kill-after=5m 5m $PROXY $f || exit 1; done
+
 # test echo server at port 8000
 HERMIT_ISLE=qemu HERMIT_CPUS=1 HERMIT_KVM=0 HERMIT_VERBOSE=1 HERMIT_APP_PORT=8000 $PROXY $TDIR/tests/server &
 sleep 10