diff --git a/weblate/machinery/base.py b/weblate/machinery/base.py
index cac38776a9b7..71efba4a1489 100644
--- a/weblate/machinery/base.py
+++ b/weblate/machinery/base.py
@@ -243,9 +243,10 @@ def report_error(
     def supported_languages(self):
         """Return list of supported languages."""
         # Try using list from cache
-        languages = cache.get(self.languages_cache)
-        if languages is not None:
-            return languages
+        languages_cache = cache.get(self.languages_cache)
+        if languages_cache is not None:
+            # hiredis-py 3 makes list from set
+            return set(languages_cache)
 
         if self.is_rate_limited():
             return set()
diff --git a/weblate/machinery/deepl.py b/weblate/machinery/deepl.py
index 370b37bdb553..d28878037375 100644
--- a/weblate/machinery/deepl.py
+++ b/weblate/machinery/deepl.py
@@ -148,13 +148,16 @@ def format_replacement(
 
     def is_glossary_supported(self, source_language: str, target_language: str) -> bool:
         cache_key = self.get_cache_key("glossary_languages")
-        languages = cache.get(cache_key)
-        if languages is None:
+        languages_cache = cache.get(cache_key)
+        if languages_cache is not None:
+            # hiredis-py 3 makes list from set
+            languages = set(languages_cache)
+        else:
             response = self.request("get", self.get_api_url("glossary-language-pairs"))
-            languages = [
+            languages = {
                 (support["source_lang"].upper(), support["target_lang"].upper())
                 for support in response.json()["supported_languages"]
-            ]
+            }
 
             cache.set(cache_key, languages, 24 * 3600)
 
diff --git a/weblate/machinery/openai.py b/weblate/machinery/openai.py
index 89944a0ef054..9f4b41b6e195 100644
--- a/weblate/machinery/openai.py
+++ b/weblate/machinery/openai.py
@@ -79,8 +79,11 @@ def is_supported(self, source, language) -> bool:
     def get_model(self) -> str:
         if self._models is None:
             cache_key = self.get_cache_key("models")
-            self._models = cache.get(cache_key)
-            if self._models is None:
+            models_cache = cache.get(cache_key)
+            if models_cache is not None:
+                # hiredis-py 3 makes list from set
+                self._models = set(models_cache)
+            else:
                 self._models = {model.id for model in self.client.models.list()}
                 cache.set(cache_key, self._models, 3600)
 
diff --git a/weblate/trans/views/dashboard.py b/weblate/trans/views/dashboard.py
index 325090a3c3ce..90600294fd68 100644
--- a/weblate/trans/views/dashboard.py
+++ b/weblate/trans/views/dashboard.py
@@ -293,8 +293,11 @@ def dashboard_user(request: AuthenticatedHttpRequest):
 
 def dashboard_anonymous(request: AuthenticatedHttpRequest):
     """Home page of Weblate showing list of projects for anonymous user."""
-    top_project_ids = cache.get("dashboard-anonymous-projects")
-    if top_project_ids is None:
+    top_project_ids_cache = cache.get("dashboard-anonymous-projects")
+    if top_project_ids_cache is not None:
+        # hiredis-py 3 makes list from set
+        top_project_ids = set(top_project_ids_cache)
+    else:
         top_projects = sorted(
             prefetch_stats(request.user.allowed_projects),
             key=lambda prj: -prj.stats.monthly_changes,