diff --git a/Tools/autotest/fg_plane_view.sh b/Tools/autotest/fg_plane_view.sh
index b70c4f5c58..d0f26bb6b3 100755
--- a/Tools/autotest/fg_plane_view.sh
+++ b/Tools/autotest/fg_plane_view.sh
@@ -2,7 +2,7 @@
 
 AUTOTESTDIR=$(dirname $0)
 
-fgfs \
+nice fgfs \
     --native-fdm=socket,in,10,,5503,udp \
     --fdm=external \
     --aircraft=Rascal110-JSBSim \
diff --git a/Tools/autotest/fg_quad_view.sh b/Tools/autotest/fg_quad_view.sh
index 9b1bb0dd9f..530a59f8a5 100755
--- a/Tools/autotest/fg_quad_view.sh
+++ b/Tools/autotest/fg_quad_view.sh
@@ -2,7 +2,7 @@
 
 AUTOTESTDIR=$(dirname $0)
 
-fgfs \
+nice fgfs \
     --native-fdm=socket,in,10,,5503,udp \
     --fdm=external \
     --aircraft=arducopter \