diff --git a/src/finiteArea/faMesh/faPatches/constraint/processor/processorFaPatch.H b/src/finiteArea/faMesh/faPatches/constraint/processor/processorFaPatch.H
index 0f0c96d81..cb3314fb5 100644
--- a/src/finiteArea/faMesh/faPatches/constraint/processor/processorFaPatch.H
+++ b/src/finiteArea/faMesh/faPatches/constraint/processor/processorFaPatch.H
@@ -170,7 +170,13 @@ public:
 
     // Member functions
 
-        //- Return processor number
+        //- Return interface size
+        virtual label interfaceSize() const
+        {
+            return size();
+        }
+
+    //- Return processor number
         int myProcNo() const
         {
             return myProcNo_;
diff --git a/src/finiteVolume/fvMesh/fvPatches/constraint/processor/processorFvPatch.H b/src/finiteVolume/fvMesh/fvPatches/constraint/processor/processorFvPatch.H
index 77fc4809b..76ecf7449 100644
--- a/src/finiteVolume/fvMesh/fvPatches/constraint/processor/processorFvPatch.H
+++ b/src/finiteVolume/fvMesh/fvPatches/constraint/processor/processorFvPatch.H
@@ -93,6 +93,12 @@ public:
 
     // Member functions
 
+        //- Return interface size
+        virtual label interfaceSize() const
+        {
+            return procPolyPatch_.size();
+        }
+
         //- Return processor number
         int myProcNo() const
         {
diff --git a/src/foam/matrices/lduMatrix/solvers/AMG/interfaces/AMGInterfaces/processorAMGInterface/processorAMGInterface.C b/src/foam/matrices/lduMatrix/solvers/AMG/interfaces/AMGInterfaces/processorAMGInterface/processorAMGInterface.C
index 5d99c36eb..08bde1ecc 100644
--- a/src/foam/matrices/lduMatrix/solvers/AMG/interfaces/AMGInterfaces/processorAMGInterface/processorAMGInterface.C
+++ b/src/foam/matrices/lduMatrix/solvers/AMG/interfaces/AMGInterfaces/processorAMGInterface/processorAMGInterface.C
@@ -157,11 +157,9 @@ Foam::processorAMGInterface::processorAMGInterface
     // All weights are equal to 1: integral matching
     restrictWeights_.setSize(localRestrictAddressing.size(), 1.0);
 
-    labelList contents = neighboursTable.toc();
-
     // Sort makes sure the order is identical on both sides.
     // HJ, 20/Feb.2009
-    sort(contents);
+    const labelList contents = neighboursTable.sortedToc();
 
     // Reset face counter for re-use
     nCoarseFaces = 0;
diff --git a/src/foam/matrices/lduMatrix/solvers/AMG/interfaces/AMGInterfaces/processorAMGInterface/processorAMGInterface.H b/src/foam/matrices/lduMatrix/solvers/AMG/interfaces/AMGInterfaces/processorAMGInterface/processorAMGInterface.H
index 60aff5b78..716b76d3a 100644
--- a/src/foam/matrices/lduMatrix/solvers/AMG/interfaces/AMGInterfaces/processorAMGInterface/processorAMGInterface.H
+++ b/src/foam/matrices/lduMatrix/solvers/AMG/interfaces/AMGInterfaces/processorAMGInterface/processorAMGInterface.H
@@ -102,6 +102,12 @@ public:
 
         // Access
 
+            //- Return interface size
+            virtual label interfaceSize() const
+            {
+                return AMGInterface::size();
+            }
+
             //- Return true if interface is coupled
             virtual bool coupled() const
             {