diff --git a/libensemble/generators.py b/libensemble/generators.py
index 5e9d957b4..9fa450123 100644
--- a/libensemble/generators.py
+++ b/libensemble/generators.py
@@ -117,7 +117,7 @@ def ask(self, num_points: Optional[int] = 0) -> List[dict]:
 
     def tell(self, results: List[dict]) -> None:
         """Send the results of evaluations to the generator."""
-        self.tell_numpy(list_dicts_to_np(results))
+        self.tell_numpy(list_dicts_to_np(results), dtype=self.gen_specs.get("out"))
 
 
 class LibensembleGenThreadInterfacer(LibensembleGenerator):