diff --git a/m-bitset.h b/m-bitset.h
index d5ddc376..2360718d 100644
--- a/m-bitset.h
+++ b/m-bitset.h
@@ -514,7 +514,6 @@ bitset_in_str(bitset_t set, FILE *file)
   if (c != '[') return false;
   c = fgetc(file);
   while (c == '0' || c == '1') {
-    if (c != '0' && c != '1') break;
     const bool b = (c == '1');
     bitset_push_back (set, b);
     c = fgetc(file);