diff --git a/src/base.cpp b/src/base.cpp
index bd263d8..9b62b11 100755
--- a/src/base.cpp
+++ b/src/base.cpp
@@ -214,6 +214,27 @@ Matrix::invert(Matrix *dst, Matrix *src)
 	return dst;
 }
 
+// transpose the 3x3 submatrix, pos is set to 0
+Matrix*
+Matrix::transpose(Matrix *dst, Matrix *src)
+{
+	if(src->flags & IDENTITY)
+		*dst = *src;
+	dst->right.x = src->right.x;
+	dst->up.x = src->right.y;
+	dst->at.x = src->right.z;
+	dst->right.y = src->up.x;
+	dst->up.y = src->up.y;
+	dst->at.y = src->up.z;
+	dst->right.z = src->at.x;
+	dst->up.z = src->at.y;
+	dst->at.z = src->at.z;
+	dst->pos.x = 0.0;
+	dst->pos.y = 0.0;
+	dst->pos.z = 0.0;
+	return dst;
+}
+
 Matrix*
 Matrix::rotate(V3d *axis, float32 angle, CombineOp op)
 {
diff --git a/src/rwbase.h b/src/rwbase.h
index 1889139..86ab804 100644
--- a/src/rwbase.h
+++ b/src/rwbase.h
@@ -227,6 +227,7 @@ struct Matrix
 	void update(void) { flags &= ~(IDENTITY|TYPEMASK); }
 	static Matrix *mult(Matrix *dst, Matrix *src1, Matrix *src2);
 	static Matrix *invert(Matrix *m1, Matrix *m2);
+	static Matrix *transpose(Matrix *m1, Matrix *m2);
 	Matrix *rotate(V3d *axis, float32 angle, CombineOp op);
 	Matrix *rotate(const Quat &q, CombineOp op);
 	Matrix *translate(V3d *translation, CombineOp op);
@@ -240,10 +241,6 @@ struct Matrix
 	static Matrix *invertGeneral(Matrix *dst, Matrix *src);
 	static void makeRotation(Matrix *dst, V3d *axis, float32 angle);
 	static void makeRotation(Matrix *dst, const Quat &q);
-/*
-	bool32 isIdentity(void);
-	static void transpose(Matrix *m1, Matrix *m2);
-*/
 private:
 	float32 normalError(void);
 	float32 orthogonalError(void);