diff --git a/libraries/AC_PID/AC_PID.cpp b/libraries/AC_PID/AC_PID.cpp
index 8ea4a5fb09..5d4cb202db 100644
--- a/libraries/AC_PID/AC_PID.cpp
+++ b/libraries/AC_PID/AC_PID.cpp
@@ -236,14 +236,6 @@ float AC_PID::get_ff()
     return _target * _kff;
 }
 
-// todo: remove function when it is no longer used.
-float AC_PID::get_ff(float target)
-{
-    float FF_out = (target * _kff);
-    _pid_info.FF = FF_out;
-    return FF_out;
-}
-
 void AC_PID::reset_I()
 {
     _integrator = 0;
diff --git a/libraries/AC_PID/AC_PID.h b/libraries/AC_PID/AC_PID.h
index 631eb1c28f..b83df07aad 100644
--- a/libraries/AC_PID/AC_PID.h
+++ b/libraries/AC_PID/AC_PID.h
@@ -50,9 +50,6 @@ public:
     float get_d() const;
     float get_ff();
 
-    // todo: remove function when it is no longer used.
-    float get_ff(float target);
-
     // reset_I - reset the integrator
     void reset_I();