diff --git a/Tools/autotest/autotest.py b/Tools/autotest/autotest.py
index 326bebaaee..3dda001933 100755
--- a/Tools/autotest/autotest.py
+++ b/Tools/autotest/autotest.py
@@ -27,7 +27,7 @@ def get_default_params(atype):
         mavproxy = util.start_MAVProxy_SIL(atype)
         idx = mavproxy.expect('Saved [0-9]+ parameters to (\S+)')
     parmfile = mavproxy.match.group(1)
-    dest = util.reltopdir('../buildlogs/%s.defaults.txt' % atype)
+    dest = util.reltopdir('../buildlogs/%s-defaults.parm' % atype)
     shutil.copy(parmfile, dest)
     util.pexpect_close(mavproxy)
     util.pexpect_close(sil)
@@ -349,15 +349,15 @@ def write_fullresults():
     results.addfile('ArduPlane build log', 'ArduPlane.txt')
     results.addfile('ArduPlane code size', 'ArduPlane.sizes.txt')
     results.addfile('ArduPlane stack sizes', 'ArduPlane.framesizes.txt')
-    results.addfile('ArduPlane defaults', 'ArduPlane.defaults.txt')
+    results.addfile('ArduPlane defaults', 'ArduPlane-defaults.parm')
     results.addfile('ArduCopter build log', 'ArduCopter.txt')
     results.addfile('ArduCopter code size', 'ArduCopter.sizes.txt')
     results.addfile('ArduCopter stack sizes', 'ArduCopter.framesizes.txt')
-    results.addfile('ArduCopter defaults', 'ArduCopter.defaults.txt')
+    results.addfile('ArduCopter defaults', 'ArduCopter-defaults.parm')
     results.addfile('APMrover2 build log', 'APMrover2.txt')
     results.addfile('APMrover2 code size', 'APMrover2.sizes.txt')
     results.addfile('APMrover2 stack sizes', 'APMrover2.framesizes.txt')
-    results.addfile('APMrover2 defaults', 'APMrover2.defaults.txt')
+    results.addfile('APMrover2 defaults', 'APMrover2-defaults.parm')
     results.addglob('APM:Libraries documentation', 'docs/libraries/index.html')
     results.addglob('APM:Plane documentation', 'docs/ArduPlane/index.html')
     results.addglob('APM:Copter documentation', 'docs/ArduCopter/index.html')