diff --git a/src/enzo/Grid_CheckForSharedFace.C b/src/enzo/Grid_CheckForSharedFace.C
index cc402f994..8adb486fb 100644
--- a/src/enzo/Grid_CheckForSharedFace.C
+++ b/src/enzo/Grid_CheckForSharedFace.C
@@ -74,7 +74,7 @@ int grid::CheckForSharedFace(grid *OtherGrid,
 
   FLOAT Lx, Ly, ShearingOffset;
 
-  if (ShearingBoundaryDirection) { // For shearing box we have another offset in the y direction
+  if (ShearingBoundaryDirection > -1) { // For shearing box we have another offset in the y direction
     Lx = (DomainRightEdge[ShearingBoundaryDirection]-DomainLeftEdge[ShearingBoundaryDirection]);
     Ly = (DomainRightEdge[ShearingVelocityDirection]-DomainLeftEdge[ShearingVelocityDirection]);
     ShearingOffset = AngularVelocity*VelocityGradient*Time*Lx;