diff --git a/GPy/util/linalg.py b/GPy/util/linalg.py
index 769624ee..2f4c4115 100644
--- a/GPy/util/linalg.py
+++ b/GPy/util/linalg.py
@@ -322,7 +322,12 @@ def cholupdate(L,x):
     N = x.size
     weave.inline(code, support_code=support_code, arg_names=['N','L','x'], type_converters=weave.converters.blitz)
 
-def backsub_both_sides(L, X):
+def backsub_both_sides(L, X,transpose='left'):
     """ Return L^-T * X * L^-1, assumuing X is symmetrical and L is lower cholesky"""
-    tmp, _ = linalg.lapack.flapack.dtrtrs(L, np.asfortranarray(X), lower=1, trans=1)
-    return linalg.lapack.flapack.dtrtrs(L, np.asfortranarray(tmp.T), lower=1, trans=1)[0].T
+    if transpose=='left':
+        tmp, _ = linalg.lapack.flapack.dtrtrs(L, np.asfortranarray(X), lower=1, trans=1)
+        return linalg.lapack.flapack.dtrtrs(L, np.asfortranarray(tmp.T), lower=1, trans=1)[0].T
+    else:
+        tmp, _ = linalg.lapack.flapack.dtrtrs(L, np.asfortranarray(X), lower=1, trans=0)
+        return linalg.lapack.flapack.dtrtrs(L, np.asfortranarray(tmp.T), lower=1, trans=0)[0].T
+