diff --git a/facto/specdb/db.py b/facto/specdb/db.py
index 6dda077..a166944 100644
--- a/facto/specdb/db.py
+++ b/facto/specdb/db.py
@@ -1298,6 +1298,56 @@
             OutArg(ArgType.Tensor),
         ],
     ),
+    Spec(
+        op="binary_cross_entropy_backward.default",  # (Tensor grad_output, Tensor self, Tensor target, Tensor? weight=None, int reduction=Mean) -> Tensor
+        inspec=[
+            InPosArg(
+                ArgType.Tensor,
+                name="grad_output",
+                constraints=[
+                    cp.Dtype.In(lambda deps: dt._floating),
+                ],
+            ),
+            InPosArg(
+                ArgType.Tensor,
+                name="self",
+                deps=[0],
+                constraints=[
+                    cp.Dtype.Eq(lambda deps: deps[0].dtype),
+                    cp.Rank.Eq(lambda deps: len(deps[0].shape)),
+                    cp.Size.Eq(lambda deps, r, d: deps[0].shape[d]),
+                ],
+            ),
+            InPosArg(
+                ArgType.Tensor,
+                name="target",
+                deps=[0, 1],
+                constraints=[
+                    cp.Dtype.Eq(lambda deps: deps[0].dtype),
+                    cp.Rank.Eq(lambda deps: len(deps[1].shape)),
+                    cp.Size.Eq(lambda deps, r, d: deps[1].shape[d]),
+                ],
+            ),
+            InPosArg(
+                ArgType.TensorOpt,
+                name="weight",
+                deps=[0, 1],
+                constraints=[
+                    cp.Dtype.Eq(lambda deps: deps[0].dtype),
+                    cp.Rank.Eq(lambda deps: len(deps[1].shape)),
+                    cp.Size.Eq(lambda deps, r, d: deps[1].shape[d]),
+                ],
+            ),
+            InPosArg(
+                ArgType.Int,
+                name="reduction",
+                constraints=[
+                    cp.Value.In(lambda deps: [0, 1, 2]),
+                ],
+            ),
+        ],
+        outspec=[OutArg(ArgType.Tensor)],
+    ),
     Spec(
         op="bitwise_and.Scalar",  # (Tensor self, Scalar other) -> Tensor
         inspec=[