diff --git a/data/shaders/shadow.geom b/data/shaders/shadow.geom
index a538974fe..2eef2aa72 100644
--- a/data/shaders/shadow.geom
+++ b/data/shaders/shadow.geom
@@ -1,23 +1,36 @@
 uniform mat4 ModelViewProjectionMatrix[4];
 
+#if __VERSION__ >= 400
+layout(triangles, invocations=4) in;
+#else
 layout(triangles) in;
+#endif
 layout(triangle_strip, max_vertices=12) out;
 
 in vec2 tc[3];
 
 out vec2 uv;
 
+void emitToLayer(int layerId)
+{
+  gl_Layer = layerId;
+  for(int i=0; i<3; i++)
+  {
+    uv = tc[i];
+    gl_Position = ModelViewProjectionMatrix[layerId] * gl_in[i].gl_Position;
+    EmitVertex();
+  }
+  EndPrimitive();
+}
+
 void main(void)
 {
+#if __VERSION__ >= 400
+  emitToLayer(gl_InvocationID);
+#else
   for (int j = 0; j<4; j++)
   {
-    gl_Layer = j;
-    for(int i=0; i<3; i++)
-    {
-      uv = tc[i];
-      gl_Position = ModelViewProjectionMatrix[j] * gl_in[i].gl_Position;
-      EmitVertex();
-    }
-    EndPrimitive();
+    emitToLayer(j);
   }
+#endif
 }