diff --git a/README.md b/README.md
index 421d6e7..e9fcbe3 100644
--- a/README.md
+++ b/README.md
@@ -57,6 +57,7 @@ It takes the following optional parameters to influence the project:
 * `--backdrop=FILE` sets a still image to place behind other elements.  This can be used to fill in the empty space in the frame.
 * `--opening-credits=FILE[:DURATION]` and `--closing-credits=FILE[:DURATION]` will add credits to project.  These can either be videos or still images (which will default to 3 seconds duration).  These options can be repeated to add multiple credits.
 * `--annotations` will include whiteboard annotations and red dot cursor to slides.
+* `--fullscreen` shows slides or screenshare in fullscreen and webcam over it.
 
 Some accepted `TIME` formats:
 
diff --git a/make-xges.py b/make-xges.py
index 977d639..2570ddb 100755
--- a/make-xges.py
+++ b/make-xges.py
@@ -33,7 +33,7 @@ class Presentation:
     def __init__(self, opts):
         self.opts = opts
         self.cam_width = round(opts.width * opts.webcam_size / 100)
-        self.slides_width = opts.width - self.cam_width
+        self.slides_width = opts.width if self.opts.fullscreen else opts.width - self.cam_width
 
         self.timeline = GES.Timeline.new_audio_video()
 
@@ -454,6 +454,8 @@ def main(argv):
                         help='File to use as closing credits (may be repeated)')
     parser.add_argument('--annotations', action='store_true', default=False,
                         help='Add annotations to slides (requires inkscape)')
+    parser.add_argument('--fullscreen', action='store_true', default=False,
+                        help='Show slides/screenshare in fullscreen and webcam over it')
     parser.add_argument('basedir', metavar='PRESENTATION-DIR', type=str,
                         help='directory containing BBB presentation assets')
     parser.add_argument('project', metavar='OUTPUT', type=str,