diff --git a/Makefile.ctr b/Makefile.ctr
index f082b28c79..c02a25948e 100644
--- a/Makefile.ctr
+++ b/Makefile.ctr
@@ -159,6 +159,10 @@ CFLAGS	+=	-mword-relocations \
 #CFLAGS	+= -Wall
 CFLAGS	+=	-DARM11 -D_3DS
 
+ifeq ($(strip $(USE_CTRULIB_2)),1)
+   CFLAGS	+= -D__3DS__
+endif
+
 ifeq ($(DEBUG), 1)
    CFLAGS	+= -O0 -g
 else
diff --git a/Makefile.ctr.salamander b/Makefile.ctr.salamander
index 1d16ede085..bcd97e3f2e 100644
--- a/Makefile.ctr.salamander
+++ b/Makefile.ctr.salamander
@@ -90,6 +90,10 @@ CFLAGS	+=	-mword-relocations \
 #CFLAGS	+= -Wall
 CFLAGS	+=	-DARM11 -D_3DS
 
+ifeq ($(strip $(USE_CTRULIB_2)),1)
+   CFLAGS	+= -D__3DS__
+endif
+
 ifeq ($(DEBUG), 1)
    CFLAGS	+= -O0 -g
 else