diff --git a/parser.py b/parser.py
index 25e45c7..328c3a5 100644
--- a/parser.py
+++ b/parser.py
@@ -14,8 +14,9 @@ def extract_adapters(files) -> Tuple[Series, List]:
     all_adapters = DataFrame()
     for entry in files:
         tables = read_html(entry)
-        adapter_sequences = tables[1].Sequence
-        all_adapters = all_adapters.append(adapter_sequences)
+        if len(tables) > 1:
+            adapter_sequences = tables[1].Sequence
+            all_adapters = all_adapters.append(adapter_sequences)
     processed_adapters = preprocess_dataframe(all_adapters)
     stats = [
         processed_adapters.str.len().mean(),