diff --git a/tests/common.sh.in b/tests/common.sh.in
index 9e8962f1a..756c20c9d 100644
--- a/tests/common.sh.in
+++ b/tests/common.sh.in
@@ -17,6 +17,9 @@ export NIX_CONF_DIR=$TEST_ROOT/etc
 export NIX_MANIFESTS_DIR=$TEST_ROOT/var/nix/manifests
 export _NIX_TEST_SHARED=$TEST_ROOT/shared
 export NIX_REMOTE=$NIX_REMOTE_
+export TEST_HOME=$TEST_ROOT/test-home
+export HOME=$TEST_HOME
+mkdir -p $TEST_HOME
 
 export PATH=@bindir@:$PATH
 
@@ -58,6 +61,10 @@ clearCache() {
     rm -rf "$cacheDir"
 }
 
+clearCacheCache() {
+    rm -f $TEST_HOME/.cache/nix/binary-cache*
+}
+
 startDaemon() {
     # Start the daemon, wait for the socket to appear.  !!!
     # ‘nix-daemon’ should have an option to fork into the background.