diff --git a/porting/npl/riot/include/syscfg/syscfg.h b/porting/npl/riot/include/syscfg/syscfg.h
index 070f059df..d007a520c 100644
--- a/porting/npl/riot/include/syscfg/syscfg.h
+++ b/porting/npl/riot/include/syscfg/syscfg.h
@@ -809,6 +809,10 @@
 #define MYNEWT_VAL_BLE_L2CAP_COC_MAX_NUM (0)
 #endif
 
+#ifndef MYNEWT_VAL_BLE_L2CAP_COC_MTU
+#define MYNEWT_VAL_BLE_L2CAP_COC_MTU (MYNEWT_VAL_MSYS_1_BLOCK_SIZE - 8)
+#endif
+
 #ifndef MYNEWT_VAL_BLE_L2CAP_JOIN_RX_FRAGS
 #define MYNEWT_VAL_BLE_L2CAP_JOIN_RX_FRAGS (1)
 #endif