diff --git a/models/dppl_hmm_semisup.jl b/models/dppl_hmm_semisup.jl
index a165e94..17dbda5 100644
--- a/models/dppl_hmm_semisup.jl
+++ b/models/dppl_hmm_semisup.jl
@@ -28,8 +28,8 @@ for t in 2:T_unsup
 end
 
 @model function dppl_hmm_semisup(K, T, T_unsup, w, z, u, alpha, beta)
-    theta ~ filldist(Dirichlet(alpha), K)
-    phi ~ filldist(Dirichlet(beta), K)
+    theta ~ product_distribution(fill(Dirichlet(alpha), K))
+    phi ~ product_distribution(fill(Dirichlet(beta), K))
     for t in 1:T
         w[t] ~ Categorical(phi[:, z[t]]);
     end