diff --git a/05_Kalman_Filters.ipynb b/05_Kalman_Filters.ipynb
index abf6d44..cc0b378 100644
--- a/05_Kalman_Filters.ipynb
+++ b/05_Kalman_Filters.ipynb
@@ -1481,8 +1481,7 @@
     "\\begin{aligned}\n",
     "\\mu_{x'}&=x+ \\frac{a}{a+b}(y-x) \\\\\n",
     "&= x + \\frac{\\sigma^2_{x'}}{b}(y-x) \\\\\n",
-    "&= x + g_n(y-x) \\\\\n",
-    "\\blacksquare\n",
+    "&= x + g_n(y-x)\n",
     "\\end{aligned}\n",
     "$$\n",
     "\n",