diff --git a/tests/lean/test.sh b/tests/lean/test.sh
index f94632525..21a4b5b75 100755
--- a/tests/lean/test.sh
+++ b/tests/lean/test.sh
@@ -3,6 +3,7 @@ if [ $# -ne 2 -a $# -ne 1 ]; then
     echo "Usage: test.sh [lean-executable-path] [yes/no]?"
     exit 1
 fi
+ulimit -s unlimited
 LEAN=$1
 if [ $# -ne 2 ]; then
     INTERACTIVE=no