diff --git a/tests/coap/Makefile b/tests/coap/Makefile
index b2ea02a8a7..34d8ae565c 100644
--- a/tests/coap/Makefile
+++ b/tests/coap/Makefile
@@ -1,8 +1,9 @@
 APPLICATION = coap
 include ../Makefile.tests_common
 
-# the MSP430 toolchain does not include assert.h
-BOARD_BLACKLIST := chronos msb-430 msb-430h telosb wsn430-v1_3b wsn430-v1_4 z1
+# the MSP430 and avr8 toolchains do not include assert.h
+BOARD_BLACKLIST := arduino-mega2560 chronos msb-430 msb-430h telosb \
+                   wsn430-v1_3b wsn430-v1_4 z1
 
 BOARD_INSUFFICIENT_RAM := redbee-econotag