diff --git a/dlibrary/dlibrary.py b/dlibrary/dlibrary.py
index 645e2e4..d82170e 100755
--- a/dlibrary/dlibrary.py
+++ b/dlibrary/dlibrary.py
@@ -44,7 +44,7 @@ ALT_VERSIONS = [
     'アヘ顔',
 ]
 
-IMAGE_FILE_EXTENSIONS = ['.png', '.jpg', '.jpeg', '.gif', '.tiff']
+IMAGE_FILE_EXTENSIONS = ['.png', '.jpg', '.jpeg', '.gif', '.tiff', '.bmp']
 
 IGNOREABLE_FILES = ['Thumbs.db', '__MACOSX', '.DS_Store']
 IGNOREABLE_EXTENSIONS = ['.txt', '.html', '.htm', '.psd', '.mp4']