diff --git a/projects/libpsl/config.site b/projects/libpsl/config.site
new file mode 100644
index 000000000..15fd89cec
--- /dev/null
+++ b/projects/libpsl/config.site
@@ -0,0 +1,5 @@
+if test "$cache_file" = /dev/null; then
+  hash=`echo $LIBS $CPPFLAGS CXXFLAGS $CFLAGS $LDFLAGS $build_alias $host_alias $target_alias \
+    | md5sum | cut -d' ' -f1`
+  cache_file=$SRC/config.cache.$CC.$hash
+fi