diff --git a/libraries/AP_HAL_ChibiOS/hwdef/f103-GPS/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/f103-GPS/hwdef.dat
index 7348b44ce4..97f3199056 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/f103-GPS/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/f103-GPS/hwdef.dat
@@ -10,8 +10,14 @@ define HAL_PROBE_EXTERNAL_I2C_COMPASSES
 undef HAL_UART_MIN_TX_SIZE
 define HAL_UART_MIN_TX_SIZE 256
 
-# GPS+MAG
+# GPS
 define HAL_PERIPH_ENABLE_GPS
+# restrict backends available on f103:
+define AP_GPS_NOVA_ENABLED 0
+define AP_GPS_SBF_ENABLED 0
+define AP_GPS_GSOF_ENABLED 0
+
+# MAG
 define HAL_PERIPH_ENABLE_MAG
 #define HAL_PERIPH_ENABLE_NCP5623_LED_WITHOUT_NOTIFY
 define HAL_PERIPH_ENABLE_TOSHIBA_LED_WITHOUT_NOTIFY
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
index 7fa212f6e4..171a23f137 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
@@ -2782,6 +2782,52 @@ def add_apperiph_defaults(f):
 #define AP_ROBOTISSERVO_ENABLED 0
 #endif
 
+/*
+ * GPS Backends - we selectively turn backends on.
+ *   Note also that f103-GPS explicitly disables some of these backends.
+ */
+#define AP_GPS_BACKEND_DEFAULT_ENABLED 0
+
+#ifndef AP_GPS_ERB_ENABLED
+#define AP_GPS_ERB_ENABLED 0
+#endif
+
+#ifndef AP_GPS_GSOF_ENABLED
+#define AP_GPS_GSOF_ENABLED defined(HAL_PERIPH_ENABLE_GPS)
+#endif
+
+#ifndef AP_GPS_NMEA_ENABLED
+#define AP_GPS_NMEA_ENABLED 0
+#endif
+
+#ifndef AP_GPS_SBF_ENABLED
+#define AP_GPS_SBF_ENABLED defined(HAL_PERIPH_ENABLE_GPS)
+#endif
+
+#ifndef AP_GPS_SBP_ENABLED
+#define AP_GPS_SBP_ENABLED 0
+#endif
+
+#ifndef AP_GPS_SBP2_ENABLED
+#define AP_GPS_SBP2_ENABLED 0
+#endif
+
+#ifndef AP_GPS_SIRF_ENABLED
+#define AP_GPS_SIRF_ENABLED 0
+#endif
+
+#ifndef AP_GPS_MAV_ENABLED
+#define AP_GPS_MAV_ENABLED 0
+#endif
+
+#ifndef AP_GPS_NOVA_ENABLED
+#define AP_GPS_NOVA_ENABLED defined(HAL_PERIPH_ENABLE_GPS)
+#endif
+
+#ifndef HAL_SIM_GPS_ENABLED
+#define HAL_SIM_GPS_ENABLED (AP_SIM_ENABLED && defined(HAL_PERIPH_ENABLE_GPS))
+#endif
+
 ''')