diff --git a/tests/asicworld/run-test.sh b/tests/asicworld/run-test.sh
index d5708c456..c22ab6928 100755
--- a/tests/asicworld/run-test.sh
+++ b/tests/asicworld/run-test.sh
@@ -11,4 +11,4 @@ do
 done
 shift "$((OPTIND-1))"
 
-exec ${MAKE:-make} -f ../tools/autotest.mk $seed EXTRA_FLAGS="-e" *.v
+exec ${MAKE:-make} -f ../tools/autotest.mk $seed EXTRA_FLAGS+="-e" *.v