diff --git a/singlem/diamond_spkg_searcher.py b/singlem/diamond_spkg_searcher.py
old mode 100644
new mode 100755
diff --git a/singlem/metagenome_otu_finder.py b/singlem/metagenome_otu_finder.py
old mode 100644
new mode 100755
index 098bbb4c..8682531d
--- a/singlem/metagenome_otu_finder.py
+++ b/singlem/metagenome_otu_finder.py
@@ -99,7 +99,7 @@ def find_windowed_sequences(self,
 
     def _find_lower_case_columns(self, protein_alignment):
         lower_cases = [False]*len(protein_alignment[0].seq)
-        lower_case_chars = re.compile(r'[a-z]')
+        lower_case_chars = re.compile(r'[a-z\*]')
         for pro in protein_alignment:
             for i, aa in enumerate(pro.seq):
                 if lower_case_chars.match(aa):