diff --git a/src/Airports/GenAirports/apt_surface.cxx b/src/Airports/GenAirports/apt_surface.cxx
index 316d0d69..9e66a5f4 100644
--- a/src/Airports/GenAirports/apt_surface.cxx
+++ b/src/Airports/GenAirports/apt_surface.cxx
@@ -198,8 +198,8 @@ TGAptSurface::TGAptSurface( const string& path,
     SG_LOG( SG_GENERAL, SG_DEBUG,
             "Area size = " << y_m << " x " << x_m << " (m)" );
 
-    int xdivs = (int)(x_m / course_grid) + 1;
-    int ydivs = (int)(y_m / course_grid) + 1;
+    int xdivs = (int)(x_m / coarse_grid) + 1;
+    int ydivs = (int)(y_m / coarse_grid) + 1;
 
     if ( xdivs < 3 ) { xdivs = 3; }
     if ( ydivs < 3 ) { ydivs = 3; }
diff --git a/src/Airports/GenAirports/global.hxx b/src/Airports/GenAirports/global.hxx
index e4319662..ac5b70d1 100644
--- a/src/Airports/GenAirports/global.hxx
+++ b/src/Airports/GenAirports/global.hxx
@@ -29,7 +29,7 @@
 extern int nudge;
 
 // Final grid size for airport surface (in meters)
-const double course_grid = 700.0;
+const double coarse_grid = 700.0;
 
 // compared to the average surface elevation, clamp all values within
 // this many meters of the average