--- _librsyncmodule.c			2009-03-16 15:36:21.000000000 +0100
+++ _librsyncmodule.c.librsync-1.0.0		2015-03-02 00:54:24.000000000 +0100
@@ -59,8 +59,13 @@
   if (sm == NULL) return NULL;
   sm->x_attr = NULL;
 
+#ifdef RS_DEFAULT_STRONG_LEN
   sm->sig_job = rs_sig_begin((size_t)blocklen,
 							 (size_t)RS_DEFAULT_STRONG_LEN);
+#else
+  sm->sig_job = rs_sig_begin((size_t)blocklen,
+							 (size_t)8, RS_MD4_SIG_MAGIC);
+#endif
   return (PyObject*)sm;
 }