diff --git a/tutorials/shaders/shader_reference/spatial_shader.rst b/tutorials/shaders/shader_reference/spatial_shader.rst
index 95c54973b..a2a85799b 100644
--- a/tutorials/shaders/shader_reference/spatial_shader.rst
+++ b/tutorials/shaders/shader_reference/spatial_shader.rst
@@ -324,6 +324,10 @@ Below is an example of a custom light function using a Lambertian lighting model
 
 If you want the lights to add together, add the light contribution to ``DIFFUSE_LIGHT`` using ``+=``, rather than overwriting it.
 
+.. warning::
+
+    In GLES2, lights will always be added together even if you override ``DIFFUSE_LIGHT`` using ``=``. This is due to lighting being computed in multiple passes (one for each light), unlike GLES3.
+
 .. warning::
 
     The ``light()`` function won't be run if the ``vertex_lighting`` render mode