diff --git a/Makefile b/Makefile
index ab7f424..62f43b3 100644
--- a/Makefile
+++ b/Makefile
@@ -33,7 +33,7 @@ CFLAGS	:=	-g -Wall -O2 -mword-relocations -save-temps \
 			-fomit-frame-pointer -ffast-math \
 			$(ARCH)
 
-CFLAGS	+=	$(INCLUDE) -DARM11 -D_3DS
+CFLAGS	+=	$(INCLUDE) -DARM11 -D_3DS -D_GNU_SOURCE
 
 CXXFLAGS	:= $(CFLAGS) -fno-rtti -fno-exceptions -std=gnu++11