diff --git a/Dockerfile b/Dockerfile
index 9cb40f5..06423ab 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.8
+FROM python:3.11-slim-buster
 RUN apt update && apt install poppler-utils -y
 COPY setup.py setup.cfg README.rst ./
 COPY refextract refextract/
diff --git a/refextract/references/api.py b/refextract/references/api.py
index 6fba533..bc28056 100644
--- a/refextract/references/api.py
+++ b/refextract/references/api.py
@@ -152,7 +152,8 @@ def extract_references_from_file(path,
         extracted_texkeys_urls = extract_texkeys_and_urls_from_pdf(path)
         if len(extracted_texkeys_urls) == len(parsed_refs):
             parsed_refs_updated = []
-            for ref, ref_texkey_urls in zip(parsed_refs, extracted_texkeys_urls):
+            for ref, ref_texkey_urls in zip(parsed_refs, extracted_texkeys_urls,
+                                            strict=False):
                 update_reference_with_urls(ref, ref_texkey_urls.get('urls', []))
                 if ref.get('url'):
                     ref['url'] = dedupe_list(ref['url'])
diff --git a/ruff.toml b/ruff.toml
index 8e81eb6..41c11f7 100644
--- a/ruff.toml
+++ b/ruff.toml
@@ -1,4 +1,4 @@
-target-version = "py38"
+target-version = "py311"
 [lint.flake8-tidy-imports]
 ban-relative-imports = "all"
 
diff --git a/tests/test_kbs.py b/tests/test_kbs.py
index 509ad22..c3968a5 100644
--- a/tests/test_kbs.py
+++ b/tests/test_kbs.py
@@ -42,7 +42,7 @@ def test_get_kbs_caches_journal_dict():
     # the cache is reused, so identity of the cache elements doesn't change
     assert all(
         cached_first is cached_second for (cached_first, cached_second)
-        in zip(first_cache["journals"], second_cache["journals"])
+        in zip(first_cache["journals"], second_cache["journals"], strict=False)
     )
 
 
@@ -55,7 +55,7 @@ def test_get_kbs_invalidates_cache_if_input_changes():
     # the cache is invalidated, so identity of the cache elements changes
     assert all(
         cached_first is not cached_second for (cached_first, cached_second)
-        in zip(first_cache["journals"], second_cache["journals"])
+        in zip(first_cache["journals"], second_cache["journals"], strict=False)
     )
     assert len(second_cache["journals"]) == 3
     assert second_cache["journals"][-1] == ["JOURNAL OF TESTING", "J TEST"]