diff --git a/libraries/AP_GPS/AP_GPS.cpp b/libraries/AP_GPS/AP_GPS.cpp
index c93206719c..3c9ede363e 100644
--- a/libraries/AP_GPS/AP_GPS.cpp
+++ b/libraries/AP_GPS/AP_GPS.cpp
@@ -22,6 +22,7 @@
 #include <AP_BoardConfig/AP_BoardConfig.h>
 #include <AP_RTC/AP_RTC.h>
 #include <climits>
+#include <AP_SerialManager/AP_SerialManager.h>
 
 #include "AP_GPS_NOVA.h"
 #include "AP_GPS_ERB.h"
diff --git a/libraries/AP_GPS/AP_GPS.h b/libraries/AP_GPS/AP_GPS.h
index 3bca1e13c9..89411ac9b5 100644
--- a/libraries/AP_GPS/AP_GPS.h
+++ b/libraries/AP_GPS/AP_GPS.h
@@ -20,7 +20,6 @@
 #include <AP_Common/Location.h>
 #include <AP_Param/AP_Param.h>
 #include "GPS_detect_state.h"
-#include <AP_SerialManager/AP_SerialManager.h>
 #include <AP_MSP/msp.h>
 #include <AP_ExternalAHRS/AP_ExternalAHRS.h>
 
@@ -219,7 +218,7 @@ public:
     };
 
     /// Startup initialisation.
-    void init(const AP_SerialManager& serial_manager);
+    void init(const class AP_SerialManager& serial_manager);
 
     /// Update GPS state based on possible bytes received from the module.
     /// This routine must be called periodically (typically at 10Hz or