diff --git a/libraries/AP_RangeFinder/AP_RangeFinder_PulsedLightLRF.cpp b/libraries/AP_RangeFinder/AP_RangeFinder_PulsedLightLRF.cpp
index 3308398548..224665b509 100644
--- a/libraries/AP_RangeFinder/AP_RangeFinder_PulsedLightLRF.cpp
+++ b/libraries/AP_RangeFinder/AP_RangeFinder_PulsedLightLRF.cpp
@@ -80,7 +80,7 @@ bool AP_RangeFinder_PulsedLightLRF::take_reading()
 }
 
 // read - return last value measured by sensor
-int AP_RangeFinder_PulsedLightLRF::read()
+int16_t AP_RangeFinder_PulsedLightLRF::read()
 {
     uint8_t buff[2];
     int16_t ret_value = 0;
diff --git a/libraries/AP_RangeFinder/AP_RangeFinder_PulsedLightLRF.h b/libraries/AP_RangeFinder/AP_RangeFinder_PulsedLightLRF.h
index 82c4421b92..cd39d152d1 100644
--- a/libraries/AP_RangeFinder/AP_RangeFinder_PulsedLightLRF.h
+++ b/libraries/AP_RangeFinder/AP_RangeFinder_PulsedLightLRF.h
@@ -90,7 +90,7 @@ public:
     bool            take_reading();
 
     // read value from sensor and return distance in cm
-    int             read();
+    int16_t         read();
 
     // heath
     bool            healthy;