diff --git a/Alignment/MuonAlignment/python/geometryXMLparser.py b/Alignment/MuonAlignment/python/geometryXMLparser.py
index a1f33f54cd3bf..92664d1b64e91 100644
--- a/Alignment/MuonAlignment/python/geometryXMLparser.py
+++ b/Alignment/MuonAlignment/python/geometryXMLparser.py
@@ -57,7 +57,7 @@ class Alignable:
     def pos(self):
         return self.x, self.y, self.z
     def covariance(self):
-        return (self.xx, self.xy, self.xz, self.xa, self.xb, self.xc), (self.xy, self.yy, self.yz), (self.xz, self.yz, self.zz)
+        return (self.xx, self.xy, self.xz, self.xa, self.xb, self.xc), (self.xy, self.yy, self.yz, self.ya, self.yb, self.yc), (self.xz, self.yz, self.zz, self.za, self.zb, self.zc), (self.xa, self.ya, self.za, self.aa, self.ab, self.ac), (self.xb, self.yb, self.zb, self.ab, self.bb, self.bc), (self.xc, self.yc, self.zc, self.ac, self.ac, self.cc)
 
 class DTAlignable:
     def index(self):