diff --git a/routing/Makefile b/routing/Makefile
index ae6bbfc..4a6f4c8 100644
--- a/routing/Makefile
+++ b/routing/Makefile
@@ -1,5 +1,5 @@
 CC = gcc
-CFLAGS = -O0 -I../include -I../../c-libp2p/include -I../../c-multiaddr/include -I../../c-protobuf -Wall
+CFLAGS = -O0 -I../include -I../../c-libp2p/include -I../../c-multiaddr/include -I../../c-protobuf -Wall -std=c99
 
 ifdef DEBUG
 CFLAGS += -g3