diff --git a/demos/opengl/camera.cpp b/demos/opengl/camera.cpp
index a785caf..2659852 100644
--- a/demos/opengl/camera.cpp
+++ b/demos/opengl/camera.cpp
@@ -260,7 +260,7 @@
 
 Vector3f Camera::unProject(const Vector2f& uv, float depth) const
 {
-    Matrix4f inv = mViewMatrix.inverse();
+    Matrix4f inv = mViewMatrix.inverse().matrix();
     return unProject(uv, depth, inv);
 }