diff --git a/include/assimp/matrix4x4.h b/include/assimp/matrix4x4.h
index 7c6905107..33f5a15b1 100644
--- a/include/assimp/matrix4x4.h
+++ b/include/assimp/matrix4x4.h
@@ -84,8 +84,8 @@ public:
 	 * @param rotation The rotation as a hamilton quaternion 
 	 * @param position The position for the x,y,z axes
 	 */
-	aiMatrix4x4t(aiVector3t<TReal>& scaling, aiQuaterniont<TReal>& rotation,
-		aiVector3t<TReal>& position);
+	aiMatrix4x4t(const aiVector3t<TReal>& scaling, const aiQuaterniont<TReal>& rotation,
+		const aiVector3t<TReal>& position);
 
 public:
 
diff --git a/include/assimp/matrix4x4.inl b/include/assimp/matrix4x4.inl
index 2d30796ab..8cde4773c 100644
--- a/include/assimp/matrix4x4.inl
+++ b/include/assimp/matrix4x4.inl
@@ -109,7 +109,7 @@ inline aiMatrix4x4t<TReal>::aiMatrix4x4t (const aiMatrix3x3t<TReal>& m)
 
 // ----------------------------------------------------------------------------------------
 template <typename TReal>
-inline aiMatrix4x4t<TReal>::aiMatrix4x4t (aiVector3t<TReal>& scaling, aiQuaterniont<TReal>& rotation, aiVector3t<TReal>& position)
+inline aiMatrix4x4t<TReal>::aiMatrix4x4t (const aiVector3t<TReal>& scaling, const aiQuaterniont<TReal>& rotation, const aiVector3t<TReal>& position)
 {
 	// build a 3x3 rotation matrix
 	aiMatrix3x3t<TReal> m = rotation.GetMatrix();