diff --git a/test/lib/inittest.sh b/test/lib/inittest.sh
index 5b3ad87d4..e3d874b6b 100644
--- a/test/lib/inittest.sh
+++ b/test/lib/inittest.sh
@@ -29,7 +29,7 @@ TESTOLDPWD=$(pwd)
 COMMON_PREFIX="LVMTEST"
 PREFIX="${COMMON_PREFIX}$$"
 
-if test -n "$LVM_TEST_DIR"; then LVM_TEST_DIR=$TMPDIR; fi
+if test -z "$LVM_TEST_DIR"; then LVM_TEST_DIR=$TMPDIR; fi
 TESTDIR=$(mkdtemp "${LVM_TEST_DIR:-/tmp}" "$PREFIX.XXXXXXXXXX") || \
 	die "failed to create temporary directory in ${LVM_TEST_DIR:-$TESTOLDPWD}"
 RUNNING_DMEVENTD=$(pgrep dmeventd) || true