diff --git a/src/lduSolvers/amg/fineAmgLevel.C b/src/lduSolvers/amg/fineAmgLevel.C
index b013865f1..b84a77454 100644
--- a/src/lduSolvers/amg/fineAmgLevel.C
+++ b/src/lduSolvers/amg/fineAmgLevel.C
@@ -263,7 +263,9 @@ void Foam::fineAmgLevel::scaleX
     // Scale x
     if
     (
-        scalingVector[0]*scalingVector[1] <= 0
+        mag(scalingVector[0]) > GREAT
+     || mag(scalingVector[1]) > GREAT
+     || scalingVector[0]*scalingVector[1] <= 0
      || mag(scalingVector[0]) < mag(scalingVector[1])
     )
     {