diff --git a/scripts/ligo.sh b/scripts/ligo.sh
index d0f9725d1..236ebe98f 100755
--- a/scripts/ligo.sh
+++ b/scripts/ligo.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 set -e
-if [ test "x$PWD" = "x" ]; then
+if test "x$PWD" = "x"; then
   echo "Cannot detect the current directory, the environment variable PWD is empty."
   exit 1
 else