diff --git a/gramps/plugins/importer/importxml.py b/gramps/plugins/importer/importxml.py
index 9d436dba4..d3e3ec8ff 100644
--- a/gramps/plugins/importer/importxml.py
+++ b/gramps/plugins/importer/importxml.py
@@ -399,7 +399,7 @@ class ImportOpenFileContextManager:
 
     def __enter__(self):
         if self.filename == '-':
-            self.filehandle = sys.stdin
+            self.filehandle = sys.stdin.buffer
         else:
             self.filehandle = self.open_file(self.filename)
         return self.filehandle