diff --git a/include/Nazara/Graphics/InstancedRenderable.hpp b/include/Nazara/Graphics/InstancedRenderable.hpp
index fb41495a6..b879f091d 100644
--- a/include/Nazara/Graphics/InstancedRenderable.hpp
+++ b/include/Nazara/Graphics/InstancedRenderable.hpp
@@ -66,7 +66,7 @@ namespace Nz
 			// Signals:
 			NazaraSignal(OnInstancedRenderableInvalidateBoundingVolume, const InstancedRenderable* /*instancedRenderable*/);
 			NazaraSignal(OnInstancedRenderableInvalidateData, const InstancedRenderable* /*instancedRenderable*/, UInt32 /*flags*/);
-			NazaraSignal(OnInstancedRenderableInvalidateMaterial, const InstancedRenderable* /*instancedRenderable*/, std::size_t /*skinIndex*/, std::size_t /*matIndex*/, MaterialRef /*newMat*/);
+			NazaraSignal(OnInstancedRenderableInvalidateMaterial, const InstancedRenderable* /*instancedRenderable*/, std::size_t /*skinIndex*/, std::size_t /*matIndex*/, const MaterialRef& /*newMat*/);
 			NazaraSignal(OnInstancedRenderableRelease, const InstancedRenderable* /*instancedRenderable*/);
 
 			struct InstanceData