diff --git a/machine_learning/adaline_learning.cpp b/machine_learning/adaline_learning.cpp
index 29eccd886..871c78074 100644
--- a/machine_learning/adaline_learning.cpp
+++ b/machine_learning/adaline_learning.cpp
@@ -22,10 +22,11 @@
 
 #include <cassert>
 #include <climits>
-#include <cstdlib>
 #include <ctime>
 #include <iostream>
 #include <vector>
+#include <cmath>
+#include <cstdlib>
 
 #define MAX_ITER 500  // INT_MAX  ///< Maximum number of iterations to learn