diff --git a/tests/conn_can/Makefile b/tests/conn_can/Makefile
index 7e895d3a01..a224fb9400 100644
--- a/tests/conn_can/Makefile
+++ b/tests/conn_can/Makefile
@@ -25,4 +25,8 @@ USEMODULE += can_trx
 FEATURES_REQUIRED += periph_can
 FEATURES_REQUIRED += periph_gpio_irq
 
+CFLAGS += -DGNRC_PKTBUF_SIZE=4096
+CFLAGS += -DCAN_PKT_BUF_SIZE=64
+CFLAGS += -DCAN_ROUTER_MAX_FILTER=32
+
 include $(RIOTBASE)/Makefile.include