diff --git a/gatchat/gatppp.c b/gatchat/gatppp.c
index bf28aae6..8dd41f89 100644
--- a/gatchat/gatppp.c
+++ b/gatchat/gatppp.c
@@ -38,7 +38,23 @@
 #include "gatppp.h"
 #include "ppp.h"
 
-#define BUFFERSZ	DEFAULT_MRU*2
+#define DEFAULT_MRU	1500
+#define DEFAULT_ACCM	0x00000000
+
+#define BUFFERSZ	(DEFAULT_MRU * 2)
+
+#define PPP_ESC		0x7d
+#define PPP_FLAG_SEQ 	0x7e
+#define PPP_ADDR_FIELD	0xff
+#define PPP_CTRL	0x03
+
+enum ppp_phase {
+	PPP_DEAD = 0,
+	PPP_ESTABLISHMENT,
+	PPP_AUTHENTICATION,
+	PPP_NETWORK,
+	PPP_TERMINATION,
+};
 
 struct _GAtPPP {
 	gint ref_count;
diff --git a/gatchat/ppp.h b/gatchat/ppp.h
index 90e22ce2..f362ffdd 100644
--- a/gatchat/ppp.h
+++ b/gatchat/ppp.h
@@ -21,28 +21,10 @@
 
 #include "ppp_cp.h"
 
-#define DEFAULT_MRU	1500
-#define DEFAULT_ACCM	0x00000000
-#define PPP_ESC		0x7d
-#define PPP_FLAG_SEQ 	0x7e
-#define PPP_ADDR_FIELD	0xff
-#define PPP_CTRL	0x03
 #define LCP_PROTOCOL	0xc021
 #define CHAP_PROTOCOL	0xc223
 #define IPCP_PROTO	0x8021
 #define PPP_IP_PROTO	0x0021
-#define PPP_HEADROOM	2
-#define HDLC_HEADROOM	3
-#define HDLC_TAIL	3
-#define MD5		5
-
-enum ppp_phase {
-	PPP_DEAD = 0,
-	PPP_ESTABLISHMENT,
-	PPP_AUTHENTICATION,
-	PPP_NETWORK,
-	PPP_TERMINATION,
-};
 
 enum ppp_event {
 	PPP_UP = 1,
diff --git a/gatchat/ppp_auth.c b/gatchat/ppp_auth.c
index e04f708d..3f69fa37 100644
--- a/gatchat/ppp_auth.c
+++ b/gatchat/ppp_auth.c
@@ -35,6 +35,8 @@
 #include "gatppp.h"
 #include "ppp.h"
 
+#define MD5	5
+
 struct chap_header {
 	guint8 code;
 	guint8 identifier;
diff --git a/gatchat/ppp_cp.c b/gatchat/ppp_cp.c
index 46c62c17..63d724d8 100644
--- a/gatchat/ppp_cp.c
+++ b/gatchat/ppp_cp.c
@@ -46,6 +46,8 @@ static const char *pppcp_state_strings[] =
 	g_free(str); \
 } while (0);
 
+#define PPP_HEADROOM	2
+
 #define pppcp_to_ppp_packet(p) \
 	(((guint8 *) p) - PPP_HEADROOM)