diff --git a/picard/util/mimetype.py b/picard/util/mimetype.py
index 040cc1c5c..014d641cb 100644
--- a/picard/util/mimetype.py
+++ b/picard/util/mimetype.py
@@ -17,6 +17,8 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
+import os
+
 MIME_TYPE_EXTENSION_MAP = {
     'image/jpeg': '.jpg',
     'image/png': '.png',