diff --git a/specdb/db.py b/specdb/db.py
index aa1dce6..5cd03d3 100644
--- a/specdb/db.py
+++ b/specdb/db.py
@@ -341,7 +341,16 @@
             ),
         ],
         outspec=[
-            OutArg(ArgType.Tensor),
+            OutArg(
+                ArgType.Tensor,
+                constraints=[
+                    cp.Dtype.In(
+                        lambda deps: dt.can_cast_from(
+                            torch.promote_types(deps[0].dtype, deps[1].dtype)
+                        )
+                    ),
+                ],
+            ),
         ],
     ),
     Spec(
@@ -373,7 +382,16 @@
             ),
         ],
         outspec=[
-            OutArg(ArgType.Tensor),
+            OutArg(
+                ArgType.Tensor,
+                constraints=[
+                    cp.Dtype.Eq(
+                        lambda deps: (
+                            fn.promote_type_with_scalar(deps[0].dtype, deps[1])
+                        )
+                    ),
+                ],
+            )
         ],
     ),
     Spec(