diff --git a/custom_libs/subliminal/video.py b/custom_libs/subliminal/video.py
index 66c090945..1dd46ccf5 100644
--- a/custom_libs/subliminal/video.py
+++ b/custom_libs/subliminal/video.py
@@ -13,10 +13,10 @@ logger = logging.getLogger(__name__)
 VIDEO_EXTENSIONS = ('.3g2', '.3gp', '.3gp2', '.3gpp', '.60d', '.ajp', '.asf', '.asx', '.avchd', '.avi', '.bik',
                     '.bix', '.box', '.cam', '.dat', '.divx', '.dmf', '.dv', '.dvr-ms', '.evo', '.flc', '.fli',
                     '.flic', '.flv', '.flx', '.gvi', '.gvp', '.h264', '.m1v', '.m2p', '.m2ts', '.m2v', '.m4e',
-                    '.m4v', '.mjp', '.mjpeg', '.mjpg', '.mkv', '.moov', '.mov', '.movhd', '.movie', '.movx', '.mp4',
-                    '.mpe', '.mpeg', '.mpg', '.mpv', '.mpv2', '.mxf', '.nsv', '.nut', '.ogg', '.ogm', '.ogv', '.omf',
-                    '.ps', '.qt', '.ram', '.rm', '.rmvb', '.swf', '.ts', '.vfw', '.vid', '.video', '.viv', '.vivo',
-                    '.vob', '.vro', '.webm', '.wm', '.wmv', '.wmx', '.wrap', '.wvx', '.wx', '.x264', '.xvid')
+                    '.m4v', '.mjp', '.mjpeg', '.mjpg', '.mk3d', '.mkv', '.moov', '.mov', '.movhd', '.movie', '.movx',
+                    '.mp4', '.mpe', '.mpeg', '.mpg', '.mpv', '.mpv2', '.mxf', '.nsv', '.nut', '.ogg', '.ogm', '.ogv',
+                    '.omf', '.ps', '.qt', '.ram', '.rm', '.rmvb', '.swf', '.ts', '.vfw', '.vid', '.video', '.viv',
+                    '.vivo', '.vob', '.vro', '.webm', '.wm', '.wmv', '.wmx', '.wrap', '.wvx', '.wx', '.x264', '.xvid')
 
 
 class Video(object):