diff --git a/pyro/distributions/conjugate.py b/pyro/distributions/conjugate.py
index ffb37f3148..ce5cc59574 100644
--- a/pyro/distributions/conjugate.py
+++ b/pyro/distributions/conjugate.py
@@ -18,7 +18,7 @@ def _log_beta_1(alpha, value, is_sparse):
     if is_sparse:
         mask = value != 0
         value, alpha, mask = torch.broadcast_tensors(value, alpha, mask)
-        result = torch.zeros_like(value)
+        result = torch.zeros_like(value, dtype=alpha.dtype)
         value = value[mask]
         alpha = alpha[mask]
         result[mask] = (