diff --git a/engine/clients/pgvector/parser.py b/engine/clients/pgvector/parser.py
index 938f39ba..326c3479 100644
--- a/engine/clients/pgvector/parser.py
+++ b/engine/clients/pgvector/parser.py
@@ -18,7 +18,7 @@ def build_condition(
         return " AND ".join(clauses)
 
     def build_exact_match_filter(self, field_name: str, value: FieldValue) -> Any:
-        return f"{field_name} == {json.dumps(value)}"
+        return f"{field_name} = {json.dumps(value)}"
 
     def build_range_filter(
         self,