diff --git a/src/OpenFOAM/meshes/boundBox/boundBox.H b/src/OpenFOAM/meshes/boundBox/boundBox.H
index 62739a1f71..e263bfdd55 100644
--- a/src/OpenFOAM/meshes/boundBox/boundBox.H
+++ b/src/OpenFOAM/meshes/boundBox/boundBox.H
@@ -74,7 +74,7 @@ public:
         //- Bits used for (x/y/z) direction encoding.
         enum directionBit : direction
         {
-            XDIR = 0x1,  //!< 0: x-direction (vector component 0)
+            XDIR = 0x1,  //!< 1: x-direction (vector component 0)
             YDIR = 0x2,  //!< 2: y-direction (vector component 1)
             ZDIR = 0x4   //!< 4: z-direction (vector component 2)
         };