diff --git a/openagent_eval/diagnosis/chunking.py b/openagent_eval/diagnosis/chunking.py
index dedf887..964ba9c 100644
--- a/openagent_eval/diagnosis/chunking.py
+++ b/openagent_eval/diagnosis/chunking.py
@@ -159,7 +159,7 @@ def _check_content_gaps(
             "will", "about", "into", "your", "some", "than",
         }
         question_words = set(
-            w.lower() for w in re.findall(r"\b[a-zA-Z]{4,}\b", question)
+            w.lower() for w in re.findall(r"\b\w{4,}\b", question)
         ) - stop_words
         if not question_words:
             return issues
diff --git a/openagent_eval/providers/base/retriever.py b/openagent_eval/providers/base/retriever.py
index 2089bac..7289933 100644
--- a/openagent_eval/providers/base/retriever.py
+++ b/openagent_eval/providers/base/retriever.py
@@ -11,7 +11,7 @@
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
-    from openagent_eval.providers.base.models import Document
+    from openagent_eval.providers.models import Document
 
 
 class Retriever(ABC):