diff --git a/src/Airports/dynamics.cxx b/src/Airports/dynamics.cxx
index 53902ac48..60289c623 100644
--- a/src/Airports/dynamics.cxx
+++ b/src/Airports/dynamics.cxx
@@ -465,7 +465,7 @@ void FGAirportDynamics::getActiveRunway(const string &trafficType, int action, s
       RunwayGroup *currRunwayGroup = 0;
       int nrActiveRunways = 0;
       time_t dayStart = fgGetLong("/sim/time/utc/day-seconds");
-      if ((fabs(dayStart - lastUpdate) > 600) || trafficType != prevTrafficType)
+      if ((abs(dayStart - lastUpdate) > 600) || trafficType != prevTrafficType)
 	{
 	  landing.clear();
 	  takeoff.clear();
diff --git a/src/Environment/environment.cxx b/src/Environment/environment.cxx
index 050bededb..6971c7c89 100644
--- a/src/Environment/environment.cxx
+++ b/src/Environment/environment.cxx
@@ -612,7 +612,7 @@ void
 FGEnvironment::_recalc_density_tropo_avg_kgm3 ()
 {
   double pressure_mb = pressure_inhg * 33.86;
-  double vaporpressure = 6.11 * pow(10, ((7.5 * dewpoint_degc) / (237.7 + dewpoint_degc)));
+  double vaporpressure = 6.11 * pow(10.0, ((7.5 * dewpoint_degc) / (237.7 + dewpoint_degc)));
 
   double virtual_temp = (temperature_degc + 273.15) / (1 - 0.379 * (vaporpressure/pressure_mb));
 
@@ -627,8 +627,8 @@ FGEnvironment::_recalc_density_tropo_avg_kgm3 ()
 void
 FGEnvironment::_recalc_relative_humidity ()
 {
-  double vaporpressure = 6.11 * pow(10, ((7.5 * dewpoint_degc) / ( 237.7 + dewpoint_degc)));
-  double sat_vaporpressure = 6.11 * pow(10, ((7.5 * temperature_degc)
+  double vaporpressure = 6.11 * pow(10.0, ((7.5 * dewpoint_degc) / ( 237.7 + dewpoint_degc)));
+  double sat_vaporpressure = 6.11 * pow(10.0, ((7.5 * temperature_degc)
       / ( 237.7 + temperature_degc)) );
   relative_humidity = 100 * vaporpressure / sat_vaporpressure ;
 }