diff --git a/tests/common.sh.in b/tests/common.sh.in
index 6c3804a25..a8d56707e 100644
--- a/tests/common.sh.in
+++ b/tests/common.sh.in
@@ -1,7 +1,5 @@
 set -e
 
-datadir="@datadir@"
-
 export TEST_ROOT=$(realpath ${TMPDIR:-/tmp}/nix-test)
 export NIX_STORE_DIR
 if ! NIX_STORE_DIR=$(readlink -f $TEST_ROOT/store 2> /dev/null); then