diff --git a/libraries/AP_GPS/AP_GPS_ERB.cpp b/libraries/AP_GPS/AP_GPS_ERB.cpp
index 80ba47de97..ff9750f19d 100644
--- a/libraries/AP_GPS/AP_GPS_ERB.cpp
+++ b/libraries/AP_GPS/AP_GPS_ERB.cpp
@@ -225,7 +225,7 @@ AP_GPS_ERB::_parse_gps(void)
 }
 
 void
-AP_GPS_ERB::inject_data(uint8_t *data, uint8_t len)
+AP_GPS_ERB::inject_data(const uint8_t *data, uint16_t len)
 {
 
     if (port->txspace() > len) {
diff --git a/libraries/AP_GPS/AP_GPS_GSOF.cpp b/libraries/AP_GPS/AP_GPS_GSOF.cpp
index 609205a3f6..d622256561 100644
--- a/libraries/AP_GPS/AP_GPS_GSOF.cpp
+++ b/libraries/AP_GPS/AP_GPS_GSOF.cpp
@@ -345,7 +345,7 @@ AP_GPS_GSOF::process_message(void)
 }
 
 void
-AP_GPS_GSOF::inject_data(uint8_t *data, uint8_t len)
+AP_GPS_GSOF::inject_data(const uint8_t *data, uint16_t len)
 {
 
     if (port->txspace() > len) {
diff --git a/libraries/AP_GPS/AP_GPS_GSOF.h b/libraries/AP_GPS/AP_GPS_GSOF.h
index e5ba6536a3..843c026435 100644
--- a/libraries/AP_GPS/AP_GPS_GSOF.h
+++ b/libraries/AP_GPS/AP_GPS_GSOF.h
@@ -35,7 +35,7 @@ public:
     // Methods
     bool read();
 
-    void inject_data(uint8_t *data, uint8_t len);
+    void inject_data(const uint8_t *data, uint16_t len) override;
 
 private:
 
diff --git a/libraries/AP_GPS/AP_GPS_MAV.cpp b/libraries/AP_GPS/AP_GPS_MAV.cpp
index 11ec17ff3d..ef05b1d3bd 100644
--- a/libraries/AP_GPS/AP_GPS_MAV.cpp
+++ b/libraries/AP_GPS/AP_GPS_MAV.cpp
@@ -41,7 +41,7 @@ bool AP_GPS_MAV::read(void)
 
 // handles an incoming mavlink message (HIL_GPS) and sets
 // corresponding gps data appropriately;
-void AP_GPS_MAV::handle_msg(mavlink_message_t *msg)
+void AP_GPS_MAV::handle_msg(const mavlink_message_t *msg)
 {
     mavlink_gps_input_t packet;
     mavlink_msg_gps_input_decode(msg, &packet);
diff --git a/libraries/AP_GPS/AP_GPS_MAV.h b/libraries/AP_GPS/AP_GPS_MAV.h
index eb632313dc..66f2f0d60a 100644
--- a/libraries/AP_GPS/AP_GPS_MAV.h
+++ b/libraries/AP_GPS/AP_GPS_MAV.h
@@ -34,7 +34,7 @@ public:
 
     static bool _detect(struct MAV_detect_state &state, uint8_t data);
 
-    void handle_msg(mavlink_message_t *msg);
+    void handle_msg(const mavlink_message_t *msg);
 
 private:
     bool _new_data;
diff --git a/libraries/AP_GPS/AP_GPS_NOVA.cpp b/libraries/AP_GPS/AP_GPS_NOVA.cpp
index 303ad56ff0..d948c04f59 100644
--- a/libraries/AP_GPS/AP_GPS_NOVA.cpp
+++ b/libraries/AP_GPS/AP_GPS_NOVA.cpp
@@ -279,7 +279,7 @@ AP_GPS_NOVA::process_message(void)
 }
 
 void
-AP_GPS_NOVA::inject_data(uint8_t *data, uint8_t len)
+AP_GPS_NOVA::inject_data(const uint8_t *data, uint16_t len)
 {
     if (port->txspace() > len) {
         last_injected_data_ms = AP_HAL::millis();
diff --git a/libraries/AP_GPS/AP_GPS_NOVA.h b/libraries/AP_GPS/AP_GPS_NOVA.h
index 72054e1b70..cc4d1d967b 100644
--- a/libraries/AP_GPS/AP_GPS_NOVA.h
+++ b/libraries/AP_GPS/AP_GPS_NOVA.h
@@ -33,7 +33,7 @@ public:
     // Methods
     bool read();
 
-    void inject_data(uint8_t *data, uint8_t len);
+    void inject_data(const uint8_t *data, uint16_t len) override;
 
 private:
 
diff --git a/libraries/AP_GPS/AP_GPS_SBF.cpp b/libraries/AP_GPS/AP_GPS_SBF.cpp
index ea967471c9..58bdeab34b 100644
--- a/libraries/AP_GPS/AP_GPS_SBF.cpp
+++ b/libraries/AP_GPS/AP_GPS_SBF.cpp
@@ -296,7 +296,7 @@ AP_GPS_SBF::process_message(void)
 }
 
 void
-AP_GPS_SBF::inject_data(uint8_t *data, uint8_t len)
+AP_GPS_SBF::inject_data(const uint8_t *data, uint16_t len)
 {
 
     if (port->txspace() > len) {
diff --git a/libraries/AP_GPS/AP_GPS_SBF.h b/libraries/AP_GPS/AP_GPS_SBF.h
index eb2a4a441b..ce185effe8 100644
--- a/libraries/AP_GPS/AP_GPS_SBF.h
+++ b/libraries/AP_GPS/AP_GPS_SBF.h
@@ -35,7 +35,7 @@ public:
     // Methods
     bool read();
 
-    void inject_data(uint8_t *data, uint8_t len);
+    void inject_data(const uint8_t *data, uint16_t len) override;
 
 private:
 
diff --git a/libraries/AP_GPS/AP_GPS_SBP.cpp b/libraries/AP_GPS/AP_GPS_SBP.cpp
index 376fa26939..e4707860ed 100644
--- a/libraries/AP_GPS/AP_GPS_SBP.cpp
+++ b/libraries/AP_GPS/AP_GPS_SBP.cpp
@@ -85,7 +85,7 @@ AP_GPS_SBP::read(void)
 }
 
 void 
-AP_GPS_SBP::inject_data(uint8_t *data, uint8_t len)
+AP_GPS_SBP::inject_data(const uint8_t *data, uint16_t len)
 {
 
     if (port->txspace() > len) {
diff --git a/libraries/AP_GPS/AP_GPS_SBP.h b/libraries/AP_GPS/AP_GPS_SBP.h
index cb279e797b..00b5b20bf4 100644
--- a/libraries/AP_GPS/AP_GPS_SBP.h
+++ b/libraries/AP_GPS/AP_GPS_SBP.h
@@ -35,7 +35,7 @@ public:
     // Methods
     bool read();
 
-    void inject_data(uint8_t *data, uint8_t len);
+    void inject_data(const uint8_t *data, uint16_t len) override;
 
     static bool _detect(struct SBP_detect_state &state, uint8_t data);
 
diff --git a/libraries/AP_GPS/AP_GPS_UBLOX.cpp b/libraries/AP_GPS/AP_GPS_UBLOX.cpp
index 56f7d77a17..3dc9dbf529 100644
--- a/libraries/AP_GPS/AP_GPS_UBLOX.cpp
+++ b/libraries/AP_GPS/AP_GPS_UBLOX.cpp
@@ -1154,7 +1154,7 @@ AP_GPS_UBLOX::_configure_rate(void)
 }
 
 void
-AP_GPS_UBLOX::inject_data(uint8_t *data, uint8_t len)
+AP_GPS_UBLOX::inject_data(const uint8_t *data, uint16_t len)
 {
     if (port->txspace() > len) {
         port->write(data, len);
diff --git a/libraries/AP_GPS/AP_GPS_UBLOX.h b/libraries/AP_GPS/AP_GPS_UBLOX.h
index f676754ca3..b380a21df7 100644
--- a/libraries/AP_GPS/AP_GPS_UBLOX.h
+++ b/libraries/AP_GPS/AP_GPS_UBLOX.h
@@ -99,7 +99,7 @@ public:
 
     static bool _detect(struct UBLOX_detect_state &state, uint8_t data);
 
-    void inject_data(uint8_t *data, uint8_t len);
+    void inject_data(const uint8_t *data, uint16_t len) override;
     
     bool is_configured(void) {
         if (!gps._auto_config) {