--- a/python/mozbuild/mozbuild/mach_commands.py
+++ b/python/mozbuild/mozbuild/mach_commands.py
@@ -819,17 +819,17 @@ class RunProgram(MachCommandBase):
     @CommandArgument('--dmd', action='store_true', group='DMD',
         help='Enable DMD. The following arguments have no effect without this.')
     @CommandArgument('--sample-below', default=None, type=str, group='DMD',
         help='Sample blocks smaller than this. Use 1 for no sampling. The default is 4093.')
     @CommandArgument('--max-frames', default=None, type=str, group='DMD',
         help='The maximum depth of stack traces. The default and maximum is 24.')
     @CommandArgument('--show-dump-stats', action='store_true', group='DMD',
         help='Show stats when doing dumps.')
-    @CommandArgument('--mode', choices=['normal', 'test', 'stress'], group='DMD',
+    @CommandArgument('--mode', choices=['normal', 'test'], group='DMD',
         help='Mode of operation. The default is normal.')
     def run(self, params, remote, background, noprofile, debug, debugger,
         debugparams, slowscript, dmd, sample_below, max_frames,
         show_dump_stats, mode):
 
         try:
             binpath = self.get_binary_path('app')
         except Exception as e: