diff --git a/libraries/AP_Proximity/AP_Proximity_LightWareSF40C_v09.cpp b/libraries/AP_Proximity/AP_Proximity_LightWareSF40C_v09.cpp
index a4df9e1575..cd8a251f84 100644
--- a/libraries/AP_Proximity/AP_Proximity_LightWareSF40C_v09.cpp
+++ b/libraries/AP_Proximity/AP_Proximity_LightWareSF40C_v09.cpp
@@ -56,7 +56,7 @@ float AP_Proximity_LightWareSF40C_v09::distance_min() const
     return 0.20f;
 }
 
-// initialise sensor (returns true if sensor is succesfully initialised)
+// initialise sensor (returns true if sensor is successfully initialised)
 bool AP_Proximity_LightWareSF40C_v09::initialise()
 {
     // set motor direction once per second
diff --git a/libraries/AP_Proximity/AP_Proximity_MAV.h b/libraries/AP_Proximity/AP_Proximity_MAV.h
index af8360fa46..c811f57c18 100644
--- a/libraries/AP_Proximity/AP_Proximity_MAV.h
+++ b/libraries/AP_Proximity/AP_Proximity_MAV.h
@@ -25,7 +25,7 @@ public:
 
 private:
 
-    // initialise sensor (returns true if sensor is succesfully initialised)
+    // initialise sensor (returns true if sensor is successfully initialised)
     bool initialise();
 
     // horizontal distance support