diff --git a/etc/caseDicts/solvers/scalarTransport/s b/etc/caseDicts/solvers/scalarTransport/s
index 15b86ff906..1bc41ad043 100644
--- a/etc/caseDicts/solvers/scalarTransport/s
+++ b/etc/caseDicts/solvers/scalarTransport/s
@@ -28,7 +28,12 @@ boundaryField
         value           uniform $sInlet;
     }
 
-    ".*"
+    outlet
+    {
+        type            zeroGradient;
+    }
+
+    wall
     {
         type            zeroGradient;
     }