diff --git a/src/Radio/itm.cpp b/src/Radio/itm.cpp
index 5fe6abc8e..1b970d067 100644
--- a/src/Radio/itm.cpp
+++ b/src/Radio/itm.cpp
@@ -39,8 +39,8 @@
 #include <assert.h>
 #include <stdio.h>
 
-const float THIRD = (1.0/3.0);
-const float f_0 = 47.7; // 47.7 MHz from [Alg 1.1], to convert frequency into wavenumber and vica versa
+const double THIRD = (1.0/3.0);
+const double f_0 = 47.7; // 47.7 MHz from [Alg 1.1], to convert frequency into wavenumber and vica versa
 
 
 using namespace std;
diff --git a/src/Radio/radio.cxx b/src/Radio/radio.cxx
index be8dc1ef3..4c80a9fe5 100644
--- a/src/Radio/radio.cxx
+++ b/src/Radio/radio.cxx
@@ -375,14 +375,14 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i
 			eps_dielect, sgm_conductivity, eno, frq_mhz, radio_climate,
 			pol, conf, rel, dbloss, strmode, p_mode, horizons, errnum);
 		if( _root_node->getBoolValue( "use-clutter-attenuation", false ) )
-			clutterLoss(frq_mhz, distance_m, itm_elev, materials, receiver_height, transmitter_height, p_mode, horizons, clutter_loss);
+			clutterLoss(frq_mhz, itm_elev, materials, receiver_height, transmitter_height, p_mode, horizons, clutter_loss);
 	}
 	else {
 		point_to_point(itm_elev, transmitter_height, receiver_height,
 			eps_dielect, sgm_conductivity, eno, frq_mhz, radio_climate,
 			pol, conf, rel, dbloss, strmode, p_mode, horizons, errnum);
 		if( _root_node->getBoolValue( "use-clutter-attenuation", false ) )
-			clutterLoss(frq_mhz, distance_m, itm_elev, materials, transmitter_height, receiver_height, p_mode, horizons, clutter_loss);
+			clutterLoss(frq_mhz, itm_elev, materials, transmitter_height, receiver_height, p_mode, horizons, clutter_loss);
 	}
 	
 	double pol_loss = 0.0;
@@ -415,11 +415,11 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i
 *	 We are only worried about clutter loss, terrain influence 
 *	 on the first Fresnel zone is calculated in the ITM functions
 ***/
-void FGRadioTransmission::clutterLoss(double freq, double distance_m, double itm_elev[], deque<string> materials,
+void FGRadioTransmission::clutterLoss(double freq, double itm_elev[], deque<string> materials,
 	double transmitter_height, double receiver_height, int p_mode,
 	double horizons[], double &clutter_loss) {
 	
-	distance_m = itm_elev[0] * itm_elev[1]; // only consider elevation points
+	double distance_m = itm_elev[0] * itm_elev[1]; // only consider elevation points
 	
 	if (p_mode == 0) {	// LOS: take each point and see how clutter height affects first Fresnel zone
 		int mat = 0;
diff --git a/src/Radio/radio.hxx b/src/Radio/radio.hxx
index 7b07d927e..ef0b19e7f 100644
--- a/src/Radio/radio.hxx
+++ b/src/Radio/radio.hxx
@@ -56,7 +56,7 @@ private:
 	double polarization_loss();
 	double ITM_calculate_attenuation(SGGeod tx_pos, double freq, int ground_to_air);
 	double LOS_calculate_attenuation(SGGeod tx_pos, double freq, int ground_to_air);
-	void clutterLoss(double freq, double distance_m, double itm_elev[], std::deque<string> materials,
+	void clutterLoss(double freq, double itm_elev[], std::deque<string> materials,
 			double transmitter_height, double receiver_height, int p_mode,
 			double horizons[], double &clutter_loss);
 	void get_material_properties(string mat_name, double &height, double &density);