diff -Nur net-snmp-5.3.0.1/snmplib/system.c net-snmp-5.3.0.1-cygwin-uptime/snmplib/system.c
--- net-snmp-5.3.0.1/snmplib/system.c	2005-08-30 02:29:24.000000000 +0200
+++ net-snmp-5.3.0.1-cygwin-uptime/snmplib/system.c	2006-01-31 02:26:09.893796100 +0100
@@ -783,7 +783,7 @@
     return lbolt;
 #endif                          /* solaris2 */
 
-#ifdef linux
+#if defined(linux) || defined(cygwin)
     FILE           *in = fopen("/proc/uptime", "r");
     long            uptim = 0, a, b;
     if (in) {
@@ -792,11 +792,7 @@
         fclose(in);
     }
     return uptim;
-#endif                          /* linux */
-
-#ifdef cygwin
-    return (0);                 /* not implemented */
-#endif
+#endif                          /* linux || cygwin */
 }
 
 #endif                          /* ! WIN32 */