diff --git a/mcp-server/src/legal_mcp/tools/precedents.py b/mcp-server/src/legal_mcp/tools/precedents.py
index fb358dc..90e3b79 100644
--- a/mcp-server/src/legal_mcp/tools/precedents.py
+++ b/mcp-server/src/legal_mcp/tools/precedents.py
@@ -52,7 +52,7 @@ async def precedent_attach(
         pdf_document_id=pdf_uuid,
         practice_area=case.get("practice_area"),
     )
-    return json.dumps(row, ensure_ascii=False, indent=2)
+    return json.dumps(row, ensure_ascii=False, indent=2, default=str)
 
 
 async def precedent_list(case_number: str) -> str:
@@ -62,7 +62,7 @@ async def precedent_list(case_number: str) -> str:
         return json.dumps({"error": f"תיק {case_number} לא נמצא."}, ensure_ascii=False)
 
     rows = await db.list_case_precedents(UUID(case["id"]))
-    return json.dumps(rows, ensure_ascii=False, indent=2)
+    return json.dumps(rows, ensure_ascii=False, indent=2, default=str)
 
 
 async def precedent_remove(precedent_id: str) -> str:
@@ -92,4 +92,4 @@ async def precedent_search_library(
         return json.dumps([], ensure_ascii=False)
 
     rows = await db.search_precedent_library(query.strip(), practice_area, limit)
-    return json.dumps(rows, ensure_ascii=False, indent=2)
+    return json.dumps(rows, ensure_ascii=False, indent=2, default=str)