diff --git a/include/Nazara/Utility/VertexDeclaration.hpp b/include/Nazara/Utility/VertexDeclaration.hpp
index a34875944..19fb6931e 100644
--- a/include/Nazara/Utility/VertexDeclaration.hpp
+++ b/include/Nazara/Utility/VertexDeclaration.hpp
@@ -17,15 +17,13 @@ class NzVertexDeclaration;
 using NzVertexDeclarationConstRef = NzResourceRef<const NzVertexDeclaration>;
 using NzVertexDeclarationRef = NzResourceRef<NzVertexDeclaration>;
 
-struct NzVertexDeclarationImpl;
-
 class NAZARA_API NzVertexDeclaration : public NzResource
 {
 	friend class NzUtility;
 
 	public:
 		NzVertexDeclaration();
-		NzVertexDeclaration(NzVertexDeclaration& declaration);
+		NzVertexDeclaration(const NzVertexDeclaration& declaration);
 		~NzVertexDeclaration();
 
 		void DisableComponent(nzVertexComponent component);
diff --git a/src/Nazara/Utility/VertexDeclaration.cpp b/src/Nazara/Utility/VertexDeclaration.cpp
index 6b09def22..dcef40e6b 100644
--- a/src/Nazara/Utility/VertexDeclaration.cpp
+++ b/src/Nazara/Utility/VertexDeclaration.cpp
@@ -18,7 +18,7 @@ m_stride(0)
 {
 }
 
-NzVertexDeclaration::NzVertexDeclaration(NzVertexDeclaration& declaration) :
+NzVertexDeclaration::NzVertexDeclaration(const NzVertexDeclaration& declaration) :
 NzResource(),
 m_stride(declaration.m_stride)
 {