diff --git a/src/calibre/debug.py b/src/calibre/debug.py
index d56b6a55ec..c10ff44994 100644
--- a/src/calibre/debug.py
+++ b/src/calibre/debug.py
@@ -59,6 +59,7 @@ as a shebang in scripts, like this:
                       help=_('Run the GUI with a debug console, logging to the'
                       ' specified path. For internal use only, use the -g'
                       ' option to run the GUI in debug mode'))
+    parser.add_option('--run-without-debug', default=False, action='store_true', help=_('Dont run python code with the DEBUG flag set'))
     parser.add_option('-w', '--viewer',  default=False, action='store_true',
                       help=_('Run the E-book viewer in debug mode'))
     parser.add_option('--paths', default=False, action='store_true',
@@ -218,7 +219,8 @@ def main(args=sys.argv):
         sys.argv = [sys.argv[0], '--multiprocessing-fork']
         exec(args[-1])
         return
-    debug()
+    if not opts.run_without_debug:
+        debug()
     if opts.gui:
         from calibre.gui_launch import calibre
         calibre(['calibre'] + args[1:])