diff --git a/optimade/server/entry_collections/entry_collections.py b/optimade/server/entry_collections/entry_collections.py
index 5af264148..2a39a94be 100644
--- a/optimade/server/entry_collections/entry_collections.py
+++ b/optimade/server/entry_collections/entry_collections.py
@@ -149,7 +149,7 @@ def find(
 
         exclude_fields = self.all_fields - response_fields
 
-        results = [self.resource_mapper.map_back(doc) for doc in raw_results]
+        results: List = [self.resource_mapper.map_back(doc) for doc in raw_results]
         self.check_and_add_missing_fields(results, response_fields)
 
         if results:
diff --git a/optimade/server/routers/utils.py b/optimade/server/routers/utils.py
index 761b6f9a1..3cad26124 100644
--- a/optimade/server/routers/utils.py
+++ b/optimade/server/routers/utils.py
@@ -260,7 +260,7 @@ def get_entries(
         links = ToplevelLinks(next=None)
 
     if exclude_fields:
-        results = remove_exclude_fields(results, exclude_fields)
+        results = remove_exclude_fields(results, exclude_fields)  # type: ignore[assignment]
 
     return response(
         links=links,
@@ -312,7 +312,7 @@ def get_single_entry(
     links = ToplevelLinks(next=None)
 
     if exclude_fields and results is not None:
-        results = remove_exclude_fields(results, exclude_fields)[0]
+        results = remove_exclude_fields(results, exclude_fields)[0]  # type: ignore[assignment]
 
     return response(
         links=links,