diff --git a/week03_lm/seminar.ipynb b/week03_lm/seminar.ipynb
index 90297594..7c2df9a3 100644
--- a/week03_lm/seminar.ipynb
+++ b/week03_lm/seminar.ipynb
@@ -191,7 +191,10 @@
     "assert len(dummy_counts[('_UNK_', '_UNK_')]) == 78\n",
     "assert dummy_counts['_UNK_', 'a']['note'] == 3\n",
     "assert dummy_counts['p', '=']['np'] == 2\n",
-    "assert dummy_counts['author', '.']['_EOS_'] == 1"
+    "assert dummy_counts['author', '.']['_EOS_'] == 1\n",
+    "\n",
+    "single_counts = count_ngrams(dummy_lines, n=1)\n",
+    "assert single_counts[()][EOS] == len(dummy_lines)"
    ]
   },
   {