diff --git a/math/perimeter.cpp b/math/perimeter.cpp
index e7777f5ca..32eda1bbc 100644
--- a/math/perimeter.cpp
+++ b/math/perimeter.cpp
@@ -11,7 +11,6 @@
 #define _USE_MATH_DEFINES
 #include <cassert>  /// for assert
 #include <cmath>    /// for M_PI definition and pow()
-#include <cmath>
 #include <cstdint>   /// for uint16_t datatype
 #include <iostream>  /// for IO operations