diff --git a/core/net/mac/contikimac.c b/core/net/mac/contikimac.c
index b4cfde02d..9021fda21 100644
--- a/core/net/mac/contikimac.c
+++ b/core/net/mac/contikimac.c
@@ -194,7 +194,7 @@ static int we_are_receiving_burst = 0;
 #ifdef CONTIKIMAC_CONF_INTER_PACKET_INTERVAL
 #define INTER_PACKET_INTERVAL              CONTIKIMAC_CONF_INTER_PACKET_INTERVAL
 #else
-#define INTER_PACKET_INTERVAL              RTIMER_ARCH_SECOND / 5000
+#define INTER_PACKET_INTERVAL              RTIMER_ARCH_SECOND / 2500
 #endif
 
 /* AFTER_ACK_DETECTECT_WAIT_TIME is the time to wait after a potential