diff --git a/glm/gtx/matrix_transform_2d.inl b/glm/gtx/matrix_transform_2d.inl
index 4d99b7aa..c1b6d683 100644
--- a/glm/gtx/matrix_transform_2d.inl
+++ b/glm/gtx/matrix_transform_2d.inl
@@ -21,11 +21,12 @@
 /// THE SOFTWARE.
 ///
 /// @ref gtx_matrix_transform_2d
-/// @file glm/gtc/gtx_matrix_transform_2d.inl
+/// @file glm/gtc/matrix_transform_2d.inl
 /// @date 2014-02-20
 /// @author Miguel Ángel Pérez Martínez
 ///////////////////////////////////////////////////////////////////////////////////
 
+#include "../trigonometric.hpp"
 
 namespace glm
 {