diff --git a/conf/firmwares/subsystems/rotorcraft/gps_udp.makefile b/conf/firmwares/subsystems/rotorcraft/gps_udp.makefile
index df238a85dc..2e66bd7722 100644
--- a/conf/firmwares/subsystems/rotorcraft/gps_udp.makefile
+++ b/conf/firmwares/subsystems/rotorcraft/gps_udp.makefile
@@ -3,7 +3,7 @@
 GPS_LED ?= none
 
 ap.srcs += $(SRC_SUBSYSTEMS)/gps.c
-ap.CFLAGS += -DGPS_TYPE_H=\"subsystems/gps/gps_udp.h\"
+ap.CFLAGS += -DPRIMARY_GPS_TYPE_H=\"subsystems/gps/gps_udp.h\"
 ap.srcs += $(SRC_SUBSYSTEMS)/gps/gps_udp.c
 
 ap.CFLAGS += -DUSE_GPS
@@ -14,5 +14,5 @@ endif
 
 nps.CFLAGS += -DUSE_GPS
 nps.srcs += $(SRC_SUBSYSTEMS)/gps.c
-nps.CFLAGS += -DGPS_TYPE_H=\"subsystems/gps/gps_sim_nps.h\"
+nps.CFLAGS += -DPRIMARY_GPS_TYPE_H=\"subsystems/gps/gps_sim_nps.h\"
 nps.srcs += $(SRC_SUBSYSTEMS)/gps/gps_sim_nps.c
diff --git a/sw/airborne/subsystems/gps/gps_udp.c b/sw/airborne/subsystems/gps/gps_udp.c
index 7c54d3e0af..3742c53f96 100644
--- a/sw/airborne/subsystems/gps/gps_udp.c
+++ b/sw/airborne/subsystems/gps/gps_udp.c
@@ -94,3 +94,10 @@ void gps_parse(void)
   }
 }
 
+/*
+ * register callbacks & structs
+ */
+void udp_gps_register(void)
+{
+  gps_register_impl(udp_gps_impl_init, gps_parse, GPS_UDP_ID, 0);
+}
diff --git a/sw/airborne/subsystems/gps/gps_udp.h b/sw/airborne/subsystems/gps/gps_udp.h
index cc50687eff..2b383fc7f6 100644
--- a/sw/airborne/subsystems/gps/gps_udp.h
+++ b/sw/airborne/subsystems/gps/gps_udp.h
@@ -3,10 +3,18 @@
 
 #include "std.h"
 
-#define GPS_NB_CHANNELS 16
+#define UDP_GPS_NB_CHANNELS 16
+
+#ifndef PrimaryGpsImpl
+#define PrimaryGpsImpl udp
+#endif
+
 
 extern void gps_parse(void);
+extern void udp_gps_impl_init(void);
+extern void udp_gps_register(void);
 
-#define GpsEvent gps_parse
+
+// #define GpsEvent gps_parse
 
 #endif /* GPS_UDP_H */