diff --git a/src/chrono_opengl/ChOpenGLCamera.cpp b/src/chrono_opengl/ChOpenGLCamera.cpp
index 32a0c62e1..7f352a9c6 100644
--- a/src/chrono_opengl/ChOpenGLCamera.cpp
+++ b/src/chrono_opengl/ChOpenGLCamera.cpp
@@ -16,6 +16,8 @@
 
 #include "chrono_opengl/ChOpenGLCamera.h"
 
+#define GLM_ENABLE_EXPERIMENTAL
+
 #include <glm/gtc/matrix_transform.hpp>
 #include <glm/gtx/rotate_vector.hpp>
 #include <glm/gtx/quaternion.hpp>
diff --git a/src/chrono_opengl/ChOpenGLViewer.cpp b/src/chrono_opengl/ChOpenGLViewer.cpp
index 68eb7c7e0..2f71c5051 100644
--- a/src/chrono_opengl/ChOpenGLViewer.cpp
+++ b/src/chrono_opengl/ChOpenGLViewer.cpp
@@ -53,6 +53,8 @@
 #include "resources/cylinder.h"
 #include "resources/cone.h"
 
+#define GLM_ENABLE_EXPERIMENTAL
+
 #include <glm/gtc/type_ptr.hpp>
 #include <glm/gtx/rotate_vector.hpp>
 #include <glm/gtc/matrix_transform.hpp>