diff --git a/mat2 b/mat2
index 0dc3b3d409e4da91d39548f94f1cfe64dd439a72..351d97b4a685f05f35b101f1d5c73d805eddb727 100755
--- a/mat2
+++ b/mat2
@@ -88,7 +88,10 @@ def __print_meta(filename: str, metadata: dict, depth: int=1):
         # Remove control characters
         # We might use 'Cc' instead of 'C', but better safe than sorry
         # https://www.unicode.org/reports/tr44/#GC_Values_Table
-        v = ''.join(ch for ch in v if not unicodedata.category(ch).startswith('C'))
+        try:
+            v = ''.join(ch for ch in v if not unicodedata.category(ch).startswith('C'))
+        except TypeError:
+            pass  # for things that aren't iterable
 
         try:  # FIXME this is ugly.
             print(padding + "  %s: %s" % (k, v))