diff --git a/numerical_methods/brent_method_extrema.cpp b/numerical_methods/brent_method_extrema.cpp
index 941c3b694..10b53b882 100644
--- a/numerical_methods/brent_method_extrema.cpp
+++ b/numerical_methods/brent_method_extrema.cpp
@@ -13,7 +13,7 @@
  *
  * \author [Krishna Vedala](https://github.com/kvedala)
  */
-#define _USE_MATH_DEFINES  //< required for MS Visual C++
+#define _USE_MATH_DEFINES  ///< required for MS Visual C++
 #include <cassert>
 #include <cmath>
 #include <functional>