diff --git a/test/test-functions b/test/test-functions
index f6a824ae693..928d3fc0ad6 100644
--- a/test/test-functions
+++ b/test/test-functions
@@ -43,6 +43,12 @@ if ! ROOTLIBDIR=$(pkg-config --variable=systemdutildir systemd); then
     ROOTLIBDIR=/usr/lib/systemd
 fi
 
+# The calling test.sh scripts have TEST_BASE_DIR set via their Makefile, but we don't need them to provide it
+TEST_BASE_DIR=${TEST_BASE_DIR:-$(realpath $(dirname "$BASH_SOURCE"))}
+TEST_UNITS_DIR="$TEST_BASE_DIR/units"
+SOURCE_DIR=$(realpath "$TEST_BASE_DIR/..")
+TOOLS_DIR="$SOURCE_DIR/tools"
+
 PATH_TO_INIT=$ROOTLIBDIR/systemd
 [ "$SYSTEMD_JOURNALD" ] || SYSTEMD_JOURNALD=$(which -a $BUILD_DIR/systemd-journald $ROOTLIBDIR/systemd-journald 2>/dev/null | grep '^/' -m1)
 [ "$SYSTEMD_JOURNAL_REMOTE" ] || SYSTEMD_JOURNAL_REMOTE=$(which -a $BUILD_DIR/systemd-journal-remote $ROOTLIBDIR/systemd-journal-remote 2>/dev/null | grep '^/' -m1)
@@ -50,7 +56,13 @@ PATH_TO_INIT=$ROOTLIBDIR/systemd
 [ "$SYSTEMD_NSPAWN" ] || SYSTEMD_NSPAWN=$(which -a $BUILD_DIR/systemd-nspawn systemd-nspawn 2>/dev/null | grep '^/' -m1)
 [ "$JOURNALCTL" ] || JOURNALCTL=$(which -a $BUILD_DIR/journalctl journalctl 2>/dev/null | grep '^/' -m1)
 
-STATEDIR="${BUILD_DIR:-.}/test/$(basename $(dirname $(realpath $0)))"
+TESTFILE=${BASH_SOURCE[1]}
+if [ -z "$TESTFILE" ]; then
+    echo "ERROR: test-functions must be sourced from one of the TEST-*/test.sh scripts" >&2
+    exit 1
+fi
+TESTNAME=$(basename $(dirname $(realpath $TESTFILE)))
+STATEDIR="$BUILD_DIR/test/$TESTNAME"
 STATEFILE="$STATEDIR/.testdir"
 IMAGESTATEDIR="$STATEDIR/.."
 TESTLOG="$STATEDIR/test.log"