diff --git a/src/foam/meshes/meshShapes/cellShape/cellShape.H b/src/foam/meshes/meshShapes/cellShape/cellShape.H
index c1aaaa7c9..f64da9652 100644
--- a/src/foam/meshes/meshShapes/cellShape/cellShape.H
+++ b/src/foam/meshes/meshShapes/cellShape/cellShape.H
@@ -74,7 +74,7 @@ class cellShape
     // Private data
 
         //- Access to the cellShape's model
-        const cellModel *m;
+        const cellModel* m_;
 
 
 public:
@@ -104,6 +104,9 @@ public:
         //- Return the points corresponding to this cellShape
         inline pointField points(const pointField& meshPoints) const;
 
+        //- Is model reference valid (model exists)
+        inline bool validModel() const;
+
         //- Model reference
         inline const cellModel& model() const;
 
diff --git a/src/foam/meshes/meshShapes/cellShape/cellShapeI.H b/src/foam/meshes/meshShapes/cellShape/cellShapeI.H
index ba177a2c1..a9ba98c05 100644
--- a/src/foam/meshes/meshShapes/cellShape/cellShapeI.H
+++ b/src/foam/meshes/meshShapes/cellShape/cellShapeI.H
@@ -30,7 +30,7 @@ License
 
 inline Foam::cellShape::cellShape()
 :
-    m(NULL)
+    m_(NULL)
 {}
 
 
@@ -42,7 +42,7 @@ inline Foam::cellShape::cellShape
 )
 :
     labelList(l),
-    m(&M)
+    m_(&M)
 {
     if (doCollapse)
     {
@@ -85,9 +85,15 @@ inline Foam::pointField Foam::cellShape::points
 }
 
 
+inline bool Foam::cellShape::validModel() const
+{
+    return m_ != NULL;
+}
+
+
 inline const Foam::cellModel& Foam::cellShape::model() const
 {
-    return *m;
+    return *m_;
 }
 
 
@@ -161,7 +167,7 @@ inline Foam::labelList Foam::cellShape::meshEdges
 
 inline Foam::faceList Foam::cellShape::faces() const
 {
-    return m->faces(*this);
+    return m_->faces(*this);
 }
 
 
@@ -216,19 +222,19 @@ inline Foam::faceList Foam::cellShape::collapsedFaces() const
 
 inline Foam::label Foam::cellShape::nFaces() const
 {
-    return m->nFaces();
+    return m_->nFaces();
 }
 
 
 inline Foam::edgeList Foam::cellShape::edges() const
 {
-    return m->edges(*this);
+    return m_->edges(*this);
 }
 
 
 inline Foam::label Foam::cellShape::nEdges() const
 {
-    return m->nEdges();
+    return m_->nEdges();
 }
 
 
@@ -240,13 +246,13 @@ inline Foam::label Foam::cellShape::nPoints() const
 
 inline Foam::point Foam::cellShape::centre(const pointField& points) const
 {
-    return m->centre(*this, points);
+    return m_->centre(*this, points);
 }
 
 
 inline Foam::scalar Foam::cellShape::mag(const pointField& points) const
 {
-    return m->mag(*this, points);
+    return m_->mag(*this, points);
 }
 
 
diff --git a/src/foam/meshes/meshShapes/cellShape/cellShapeIO.C b/src/foam/meshes/meshShapes/cellShape/cellShapeIO.C
index 7cf766410..23a51103a 100644
--- a/src/foam/meshes/meshShapes/cellShape/cellShapeIO.C
+++ b/src/foam/meshes/meshShapes/cellShape/cellShapeIO.C
@@ -64,11 +64,11 @@ Istream& operator>>(Istream& is, cellShape& s)
     // it is allowed to have either a word or a number describing the model
     if (t.isLabel())
     {
-        s.m = cellModeller::lookup(int(t.labelToken()));
+        s.m_ = cellModeller::lookup(int(t.labelToken()));
     }
     else if (t.isWord())
     {
-        s.m = cellModeller::lookup(t.wordToken());
+        s.m_ = cellModeller::lookup(t.wordToken());
     }
     else
     {
@@ -79,11 +79,12 @@ Istream& operator>>(Istream& is, cellShape& s)
     }
 
     // Check that a model was found
-    if (!s.m)
+    if (!s.m_)
     {
         FatalIOErrorIn("operator>>(Istream& is, cellShape& s)", is)
             << "CellShape has unknown model " << t.info()
             << exit(FatalIOError);
+
         return is;
     }
 
@@ -106,10 +107,10 @@ Ostream& operator<<(Ostream& os, const cellShape & s)
     os << token::BEGIN_LIST;
 
     // Write the list label for the symbol (ONE OR THE OTHER !!!)
-    os << (s.m)->index() << token::SPACE;
+    os << (s.m_)->index() << token::SPACE;
 
     // Write the model name instead of the label (ONE OR THE OTHER !!!)
-    // os << (s.m)->name() << token::SPACE;
+    // os << (s.m_)->name() << token::SPACE;
 
     // Write the geometry
     os << static_cast<const labelList&>(s);
@@ -128,7 +129,7 @@ Ostream& operator<<(Ostream& os, const InfoProxy<cellShape>& ip)
 {
     const cellShape& cs = ip.t_;
 
-    if (!(&cs.model()))
+    if (!cs.validModel())
     {
         os  << "    cellShape has no model!\n";
     }