diff --git a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/dataExchangeModel/dataExchangeModel.C b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/dataExchangeModel/dataExchangeModel.C
index ddee3673..723db484 100755
--- a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/dataExchangeModel/dataExchangeModel.C
+++ b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/dataExchangeModel/dataExchangeModel.C
@@ -195,7 +195,7 @@ void dataExchangeModel::destroy(double* array) const
 //====
 
 
-bool dataExchangeModel::couple(int i) const
+bool dataExchangeModel::couple(int i)
 {
     bool coupleNow = false;
     if (doCoupleNow())
diff --git a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/dataExchangeModel/dataExchangeModel.H b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/dataExchangeModel/dataExchangeModel.H
index e864bfee..1cfcce94 100755
--- a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/dataExchangeModel/dataExchangeModel.H
+++ b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/dataExchangeModel/dataExchangeModel.H
@@ -62,7 +62,7 @@ protected:
 
         int maxNumberOfParticles_;
 
-        mutable int couplingStep_;
+        int couplingStep_;
 
         scalar DEMts_;
 
@@ -176,7 +176,7 @@ public:
         virtual void destroy(double*) const;
         //====
 
-        virtual bool couple(int) const;
+        virtual bool couple(int);
 
         virtual scalar timeStepFraction() const;
 
diff --git a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMPI/twoWayMPI.C b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMPI/twoWayMPI.C
index 9d142ed1..875399fa 100644
--- a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMPI/twoWayMPI.C
+++ b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMPI/twoWayMPI.C
@@ -204,7 +204,7 @@ void twoWayMPI::destroy(double* array) const
 }
 //============
 
-bool twoWayMPI::couple(int i) const
+bool twoWayMPI::couple(int i)
 {
     bool coupleNow = false;
     if (i==0)
diff --git a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMPI/twoWayMPI.H b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMPI/twoWayMPI.H
index dbf40c9a..5c643534 100644
--- a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMPI/twoWayMPI.H
+++ b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMPI/twoWayMPI.H
@@ -151,7 +151,7 @@ public:
         void destroy(int*) const;
         //==============
 
-        bool couple(int) const;
+        bool couple(int);
 
         int getNumberOfParticles() const;
         int getNumberOfClumps() const;
diff --git a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMany2Many/twoWayMany2Many.C b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMany2Many/twoWayMany2Many.C
index bbdf952d..90334d17 100644
--- a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMany2Many/twoWayMany2Many.C
+++ b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMany2Many/twoWayMany2Many.C
@@ -384,7 +384,7 @@ void inline twoWayMany2Many::destroy(int* array) const
 //==============
 
 
-bool twoWayMany2Many::couple(int i) const
+bool twoWayMany2Many::couple(int i)
 {
     bool coupleNow = false;
     if (i==0)
diff --git a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMany2Many/twoWayMany2Many.H b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMany2Many/twoWayMany2Many.H
index 96d8fc25..8c7e2db7 100644
--- a/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMany2Many/twoWayMany2Many.H
+++ b/src/lagrangian/cfdemParticle/subModels/dataExchangeModel/twoWayMany2Many/twoWayMany2Many.H
@@ -201,7 +201,7 @@ public:
         void inline destroy(int*) const;
         //==============
 
-        bool couple(int) const;
+        bool couple(int);
 
         int getNumberOfParticles() const;
         int getNumberOfClumps() const;