diff --git a/libraries/SITL/SITL.cpp b/libraries/SITL/SITL.cpp
index f5c24a31fd..a0190e2be5 100644
--- a/libraries/SITL/SITL.cpp
+++ b/libraries/SITL/SITL.cpp
@@ -132,8 +132,8 @@ void SITL::convert_body_frame(double rollDeg, double pitchDeg,
 	thetaDot = ToRad(pitchRate);
 	psiDot = ToRad(yawRate);
 
-	*p = phiDot - psiDot*sin(theta);
-	*q = cos(phi)*thetaDot + sin(phi)*psiDot*cos(theta);
-	*r = cos(phi)*psiDot*cos(theta) - sin(phi)*thetaDot;    
+	*p = phiDot - psiDot*sinf(theta);
+	*q = cosf(phi)*thetaDot + sinf(phi)*psiDot*cosf(theta);
+	*r = cosf(phi)*psiDot*cosf(theta) - sinf(phi)*thetaDot;    
 }