diff --git a/InnerDetector/InDetRecEvent/InDetPrepRawData/InDetPrepRawData/PixelGangedClusterAmbiguities.h b/InnerDetector/InDetRecEvent/InDetPrepRawData/InDetPrepRawData/PixelGangedClusterAmbiguities.h
index 3e044d86b77a5733338073f10ca48b624e2cde7f..fe1968a56e7414ced3fe96f9a3ebbc47e7e089d9 100755
--- a/InnerDetector/InDetRecEvent/InDetPrepRawData/InDetPrepRawData/PixelGangedClusterAmbiguities.h
+++ b/InnerDetector/InDetRecEvent/InDetPrepRawData/InDetPrepRawData/PixelGangedClusterAmbiguities.h
@@ -26,6 +26,13 @@ namespace InDet{
     {
       Identifier ida = (a!=0 ? a->identify() : Identifier(0));
       Identifier idb = (b!=0 ? b->identify() : Identifier(0));
+
+      // sometimes different clusters have the same identity
+      // use the size to determine the order/break degeneracy
+      if( ida == idb && ida != Identifier(0) ) { 
+        return (a->width() < b->width());
+      }
+        
       return ida < idb;
     }
   };
diff --git a/InnerDetector/InDetRecEvent/InDetPrepRawData/InDetPrepRawData/SiWidth.h b/InnerDetector/InDetRecEvent/InDetPrepRawData/InDetPrepRawData/SiWidth.h
index 563e23dfab39c45b091f5d126292919c86cc235f..f7663d62483c4bba5b87d743de952c757d3c0f29 100755
--- a/InnerDetector/InDetRecEvent/InDetPrepRawData/InDetPrepRawData/SiWidth.h
+++ b/InnerDetector/InDetRecEvent/InDetPrepRawData/InDetPrepRawData/SiWidth.h
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
 
 ///////////////////////////////////////////////////////////////////
@@ -63,6 +63,9 @@ namespace InDet {
    // return z
    double z() const;
 
+   // comparison
+   bool operator <(const SiWidth& width) const;
+   bool operator >(const SiWidth& width) const;
 
    ///////////////////////////////////////////////////////////////////
    // Non-const methods:
@@ -128,6 +131,28 @@ namespace InDet {
   {
     return m_phirzWidth[Trk::locZ];    
   }
+
+  // comparison
+  // return true if smaller in either direction
+  inline bool InDet::SiWidth::operator <(const InDet::SiWidth &width) const
+  {
+    // size phi
+    if ( m_colrow[0] < width.colRow()[0] ) { return true; }
+    // size z
+    if ( m_colrow[1] < width.colRow()[1] ) { return true; }
+    return false;
+  }
+
+  // flip logic of <
+  inline bool InDet::SiWidth::operator >(const InDet::SiWidth &width) const
+  {
+    // size phi
+    if ( m_colrow[0] < width.colRow()[0] ) { return false; }
+    // size z
+    if ( m_colrow[1] < width.colRow()[1] ) { return false; }
+    return true;
+  }
+
   
   inline void SiWidth::setColumn(const double col)
   {
@@ -137,7 +162,7 @@ namespace InDet {
   inline void SiWidth::setRow(const double row)
   {
    m_colrow[1] = row;
-   }
+  }
 
   inline void SiWidth::setColRow(const Amg::Vector2D& colRow)
   {