diff --git a/demos/Wiener_Filter.ipynb b/demos/Wiener_Filter.ipynb
index df369506d6f0d8e9c70244d81dc3e9283467f363..f6ec32a6911bd90a52a5256e1a069dbb9430064b 100644
--- a/demos/Wiener_Filter.ipynb
+++ b/demos/Wiener_Filter.ipynb
@@ -58,7 +58,7 @@
     "### Posterior\n",
     "The Posterior is given by:\n",
     "\n",
-    "$$\\mathcal P (s|d) \\propto P(s,d) = \\mathcal G(d-Rs,N) \\,\\mathcal G(s,S) \\propto \\mathcal G (m,D) $$\n",
+    "$$\\mathcal P (s|d) \\propto P(s,d) = \\mathcal G(d-Rs,N) \\,\\mathcal G(s,S) \\propto \\mathcal G (s-m,D) $$\n",
     "\n",
     "where\n",
     "$$\\begin{align}\n",