diff --git a/CHANGELOG b/CHANGELOG
index b0a3ba04..d7ece291 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -33,6 +33,9 @@ HISTORY
 
   ++ Bugfixes:
 
+  2010-01-07: Simon Goldschmidt
+  * timers.c, tcp.h: Call tcp_timer_needed() with NO_SYS==1, too
+
   2010-01-06: Simon Goldschmidt
   * netdb.h: Fixed bug #28496: missing include guards in netdb.h
 
diff --git a/src/core/timers.c b/src/core/timers.c
index 6dcc2dd0..d5f17d4a 100644
--- a/src/core/timers.c
+++ b/src/core/timers.c
@@ -87,7 +87,6 @@ tcpip_tcp_timer(void *arg)
   }
 }
 
-#if !NO_SYS
 /**
  * Called from TCP_REG when registering a new PCB:
  * the reason is to have the TCP timer only running when
@@ -103,7 +102,6 @@ tcp_timer_needed(void)
     sys_timeout(TCP_TMR_INTERVAL, tcpip_tcp_timer, NULL);
   }
 }
-#endif /* !NO_SYS */
 #endif /* LWIP_TCP */
 
 #if IP_REASSEMBLY
diff --git a/src/include/lwip/tcp.h b/src/include/lwip/tcp.h
index 0469ce7a..661d2ec6 100644
--- a/src/include/lwip/tcp.h
+++ b/src/include/lwip/tcp.h
@@ -610,11 +610,7 @@ s16_t tcp_pcbs_sane(void);
 #  define tcp_pcbs_sane() 1
 #endif /* TCP_DEBUG */
 
-#if NO_SYS
-#define tcp_timer_needed()
-#else
 void tcp_timer_needed(void);
-#endif
 
 /* The TCP PCB lists. */
 union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */