diff --git a/conf/modules/gps_ublox.xml b/conf/modules/gps_ublox.xml
index ed7e0a9c52..dba5b8870c 100644
--- a/conf/modules/gps_ublox.xml
+++ b/conf/modules/gps_ublox.xml
@@ -1,6 +1,6 @@
 <!DOCTYPE module SYSTEM "module.dtd">
 
-<module name="gps_ublox">
+<module name="gps_ublox" dir="gps">
   <doc>
     <description>
       U-blox GPS (UART)
diff --git a/sw/airborne/modules/gps/gps_ubx_i2c.c b/sw/airborne/modules/gps/gps_ubx_i2c.c
index 0cd0312cd3..dc02fc294b 100644
--- a/sw/airborne/modules/gps/gps_ubx_i2c.c
+++ b/sw/airborne/modules/gps/gps_ubx_i2c.c
@@ -38,7 +38,7 @@
 #define GPS_I2C_SLAVE_ADDR (0x42 << 1)
 
 #ifndef GPS_UBX_I2C_DEV
-#define GPS_UBX_I2C_DEV i2c2
+#error "GPS_UBX_I2C_DEV needs to be defined (e.g. to i2c1)"
 #endif
 PRINT_CONFIG_VAR(GPS_UBX_I2C_DEV)