diff -up echoping-6.0.2_r434/echoping.c.orig echoping-6.0.2_r434/echoping.c
--- echoping-6.0.2_r434/echoping.c.orig	2015-02-25 15:41:46.543676359 +0100
+++ echoping-6.0.2_r434/echoping.c	2015-02-25 15:42:43.262222690 +0100
@@ -471,7 +471,7 @@ main(argc, argv)
     if (plugin_name) {
         ext = strstr(plugin_name, ".so");
         if ((ext == NULL) || (strcmp(ext, ".so") != 0))
-            sprintf(plugin_name, "%s.so", plugin_name);
+            strcat(plugin_name, ".so");
         plugin = dlopen(plugin_name, RTLD_NOW);
         if (!plugin) {
             /* Retries with the absolute name */