diff --git a/include/Nazara/Utility/TriangleIterator.hpp b/include/Nazara/Utility/TriangleIterator.hpp
index 32467660a..2429c4973 100644
--- a/include/Nazara/Utility/TriangleIterator.hpp
+++ b/include/Nazara/Utility/TriangleIterator.hpp
@@ -34,6 +34,8 @@ class NAZARA_API NzTriangleIterator
 		void SetTangent(unsigned int i, const NzVector3f& tangent);
 		void SetTexCoords(unsigned int i, const NzVector2f& texCoords);
 
+		void Unmap();
+
 	private:
 		nzPrimitiveType m_primitiveType;
 		nzUInt32 m_triangleIndices[3];
diff --git a/src/Nazara/Utility/TriangleIterator.cpp b/src/Nazara/Utility/TriangleIterator.cpp
index 88cad52c7..176a7c798 100644
--- a/src/Nazara/Utility/TriangleIterator.cpp
+++ b/src/Nazara/Utility/TriangleIterator.cpp
@@ -29,9 +29,7 @@ bool NzTriangleIterator::Advance()
 {
 	if (m_currentIndex >= m_indexCount)
 	{
-		///FIXME: Que faire si Advance() est appelé deux fois
-		m_indexMapper.Unmap();
-		m_vertexMapper.Unmap();
+		Unmap();
 		return false;
 	}
 
@@ -164,3 +162,10 @@ void NzTriangleIterator::SetTexCoords(unsigned int i, const NzVector2f& texCoord
 
 	m_vertexMapper.SetTexCoords(m_triangleIndices[i], texCoords);
 }
+
+void NzTriangleIterator::Unmap()
+{
+	// Peut très bien être appellé plusieurs fois de suite, seul le premier appel sera pris en compte
+	m_indexMapper.Unmap();
+	m_vertexMapper.Unmap();
+}
diff --git a/src/Nazara/Utility/VertexMapper.cpp b/src/Nazara/Utility/VertexMapper.cpp
index e0504b764..39c3271b5 100644
--- a/src/Nazara/Utility/VertexMapper.cpp
+++ b/src/Nazara/Utility/VertexMapper.cpp
@@ -326,6 +326,9 @@ void NzVertexMapper::SetTexCoords(unsigned int i, const NzVector2f& texCoords)
 
 void NzVertexMapper::Unmap()
 {
-	delete m_impl;
-	m_impl = nullptr;
+	if (m_impl)
+	{
+		delete m_impl;
+		m_impl = nullptr;
+	}
 }