diff --git a/code/nel/include/nel/3d/computed_string.h b/code/nel/include/nel/3d/computed_string.h
index fcb758da4..517200383 100644
--- a/code/nel/include/nel/3d/computed_string.h
+++ b/code/nel/include/nel/3d/computed_string.h
@@ -290,7 +290,7 @@ public:
 	 * \param matrix transformation matrix
 	 * \param hotspot position of string origine
 	 */
-	void render3D (IDriver& driver,CMatrix matrix,THotSpot hotspot = MiddleMiddle);
+	void render3D (IDriver& driver, const CMatrix &matrix, THotSpot hotspot = MiddleMiddle);
 
 };
 
diff --git a/code/nel/include/nel/misc/matrix.h b/code/nel/include/nel/misc/matrix.h
index 700eb4a14..37a19b655 100644
--- a/code/nel/include/nel/misc/matrix.h
+++ b/code/nel/include/nel/misc/matrix.h
@@ -53,6 +53,7 @@ class	CPlane;
  * \author Nevrax France
  * \date 2000
  */
+NL_ALIGN_SSE2
 class CMatrix
 {
 public:
diff --git a/code/nel/src/3d/computed_string.cpp b/code/nel/src/3d/computed_string.cpp
index a57191cc0..1a9fefba5 100644
--- a/code/nel/src/3d/computed_string.cpp
+++ b/code/nel/src/3d/computed_string.cpp
@@ -143,11 +143,13 @@ void CComputedString::render2D (IDriver& driver,
 /*------------------------------------------------------------------*\
 							render3D()
 \*------------------------------------------------------------------*/
-void CComputedString::render3D (IDriver& driver,CMatrix matrix,THotSpot hotspot)
+void CComputedString::render3D (IDriver& driver, const CMatrix &matrixp, THotSpot hotspot)
 {
 	if (Vertices.getNumVertices() == 0)
 		return;
 
+	CMatrix matrix = matrixp;
+
 	// get window size
 	uint32	wndWidth, wndHeight;
 	driver.getWindowSize(wndWidth, wndHeight);