diff --git a/docs/notebooks/hmm/casino_hmm_learning.ipynb b/docs/notebooks/hmm/casino_hmm_learning.ipynb
index 92eff386..0fbba227 100644
--- a/docs/notebooks/hmm/casino_hmm_learning.ipynb
+++ b/docs/notebooks/hmm/casino_hmm_learning.ipynb
@@ -29,7 +29,7 @@
     "\\begin{align*}\n",
     "p(\\theta) &= \\mathrm{Dir}(\\pi \\mid \\alpha 1_K) \\prod_{k=1}^K \\mathrm{Dir}(A_k \\mid \\beta 1_K) \\, \\mathrm{Dir}(B_k \\mid \\gamma 1_C)\n",
     "\\end{align*}\n",
-    "The hyperparameters can be specified in the [`CategoricalHMM`](https://probml.github.io/dynamax/api.html#dynamax.hidden_markov_model.CategoricalHMM) constructor..\n",
+    "The hyperparameters can be specified in the [`CategoricalHMM`](https://probml.github.io/dynamax/api.html#dynamax.hidden_markov_model.CategoricalHMM) constructor.\n",
     "\n",
     "The **learning objective** is to find parameters that maximize the marginal probability,\n",
     "\\begin{align*}\n",