diff --git a/src/server/tmp-difftime.h b/src/server/tmp-difftime.h
new file mode 100644
index 0000000000000000000000000000000000000000..cf8028425654cad06ed0a40e348c7b8aca740f63
--- /dev/null
+++ b/src/server/tmp-difftime.h
@@ -0,0 +1,3 @@
+/* This file should be removed as soon as possible. autoconf should
+   fix this instead. */
+extern double difftime(time_t t1, time_t t2);