diff --git a/src/FDM/flight.cxx b/src/FDM/flight.cxx
index 248685ba0..1f4a6acfc 100644
--- a/src/FDM/flight.cxx
+++ b/src/FDM/flight.cxx
@@ -490,7 +490,7 @@ FGInterface::unbind ()
   fgUntie("/orientation/side-slip-deg");
   fgUntie("/orientation/alpha-deg");
   fgUntie("/velocities/airspeed-kt");
-   fgUntie("/velocities/groundspeed-kt");
+  fgUntie("/velocities/groundspeed-kt");
   fgUntie("/velocities/mach");
   fgUntie("/velocities/speed-north-fps");
   fgUntie("/velocities/speed-east-fps");