diff --git a/python/JSBSim.py b/python/JSBSim.py
index c89d977c42..93166cfd4d 100644
--- a/python/JSBSim.py
+++ b/python/JSBSim.py
@@ -53,7 +53,7 @@
                     help="specifies to suspend the simulation after initialization")
 parser.add_argument("--initfile", metavar="<filename>",
                     help="specifies an initialization file")
-parser.add_argument("--planetfile", metavar="<filename>",
+parser.add_argument("--planet", metavar="<filename>",
                     help="specifies a planet definition file")
 parser.add_argument("--catalog", default=False, action="store_true",
                     help="specifies that all properties for this aircraft model should be printed")
diff --git a/src/JSBSim.cpp b/src/JSBSim.cpp
index fb608fbf50..09090efbf4 100644
--- a/src/JSBSim.cpp
+++ b/src/JSBSim.cpp
@@ -795,7 +795,7 @@ void PrintHelp(void)
     cout << "    --nohighlight  specifies that console output should be pure text only (no color)" << endl;
     cout << "    --suspend  specifies to suspend the simulation after initialization" << endl;
     cout << "    --initfile=<filename>  specifies an initilization file" << endl;
-    cout << "    --planetfile=<filename>  specifies a planet definition file" << endl;
+    cout << "    --planet=<filename>  specifies a planet definition file" << endl;
     cout << "    --catalog specifies that all properties for this aircraft model should be printed" << endl;
     cout << "              (catalog=aircraftname is an optional format)" << endl;
     cout << "    --property=<name=value> e.g. --property=simulation/integrator/rate/rotational=1" << endl;