diff --git a/tests/liberty/.gitignore b/tests/liberty/.gitignore
index bf5ba57dc..8763aaac5 100644
--- a/tests/liberty/.gitignore
+++ b/tests/liberty/.gitignore
@@ -1,4 +1,3 @@
 *.log
-test.ys
 *.filtered
 *.verilogsim
diff --git a/tests/liberty/run-test.sh b/tests/liberty/run-test.sh
index 07d2cce1c..771bb69f7 100755
--- a/tests/liberty/run-test.sh
+++ b/tests/liberty/run-test.sh
@@ -3,10 +3,7 @@ set -e
 
 for x in *.lib; do
 	echo "Testing on $x.."
-	echo "read_verilog small.v" > test.ys
-	echo "synth -top small" >> test.ys
-	echo "dfflibmap -info -liberty ${x}" >> test.ys
-	../../yosys -ql ${x%.lib}.log -s test.ys
+	../../yosys -p "read_verilog small.v; synth -top small; dfflibmap -info -liberty ${x}" -ql ${x%.lib}.log
 	../../yosys-filterlib - $x 2>/dev/null > $x.filtered
 	../../yosys-filterlib -verilogsim $x > $x.verilogsim
 	diff $x.filtered $x.filtered.ok && diff $x.verilogsim $x.verilogsim.ok