diff --git a/tests/verific/run-test.sh b/tests/verific/run-test.sh
index 2e340916d..1666ee1f9 100755
--- a/tests/verific/run-test.sh
+++ b/tests/verific/run-test.sh
@@ -2,4 +2,4 @@
 set -eu
 source ../gen-tests-makefile.sh
 generate_mk --yosys-scripts --bash
-sed -i '1i\export ASAN_OPTIONS=halt_on_error=0' run-test.mk
+{ echo 'export ASAN_OPTIONS=halt_on_error=0'; cat run-test.mk; } > run-test.mk.tmp && mv run-test.mk.tmp run-test.mk