diff --git a/unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h b/unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h
index e5d4e3ad2..221ec3115 100644
--- a/unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h
+++ b/unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h
@@ -435,8 +435,6 @@ template<typename Derived> struct MatrixExponentialReturnValue
 
   protected:
     const Derived& m_src;
-  private:
-    MatrixExponentialReturnValue& operator=(const MatrixExponentialReturnValue&);
 };
 
 namespace internal {
diff --git a/unsupported/Eigen/src/MatrixFunctions/MatrixFunction.h b/unsupported/Eigen/src/MatrixFunctions/MatrixFunction.h
index a5476ac26..ad54d8ed0 100644
--- a/unsupported/Eigen/src/MatrixFunctions/MatrixFunction.h
+++ b/unsupported/Eigen/src/MatrixFunctions/MatrixFunction.h
@@ -527,8 +527,6 @@ template<typename Derived> class MatrixFunctionReturnValue
   private:
     typename internal::nested<Derived>::type m_A;
     StemFunction *m_f;
-
-    MatrixFunctionReturnValue& operator=(const MatrixFunctionReturnValue&);
 };
 
 namespace internal {
diff --git a/unsupported/Eigen/src/MatrixFunctions/MatrixLogarithm.h b/unsupported/Eigen/src/MatrixFunctions/MatrixLogarithm.h
index 586c034af..32ec385e0 100644
--- a/unsupported/Eigen/src/MatrixFunctions/MatrixLogarithm.h
+++ b/unsupported/Eigen/src/MatrixFunctions/MatrixLogarithm.h
@@ -454,8 +454,6 @@ public:
   
 private:
   typename internal::nested<Derived>::type m_A;
-  
-  MatrixLogarithmReturnValue& operator=(const MatrixLogarithmReturnValue&);
 };
 
 namespace internal {
diff --git a/unsupported/Eigen/src/MatrixFunctions/MatrixPower.h b/unsupported/Eigen/src/MatrixFunctions/MatrixPower.h
index 5d580ac9e..e0a687978 100644
--- a/unsupported/Eigen/src/MatrixFunctions/MatrixPower.h
+++ b/unsupported/Eigen/src/MatrixFunctions/MatrixPower.h
@@ -34,7 +34,6 @@ class MatrixPowerRetval : public ReturnByValue< MatrixPowerRetval<MatrixType> >
   private:
     MatrixPower<MatrixType>& m_pow;
     const RealScalar m_p;
-    MatrixPowerRetval& operator=(const MatrixPowerRetval&);
 };
 
 template<typename MatrixType>
@@ -500,7 +499,6 @@ class MatrixPowerReturnValue : public ReturnByValue< MatrixPowerReturnValue<Deri
   private:
     const Derived& m_A;
     const RealScalar m_p;
-    MatrixPowerReturnValue& operator=(const MatrixPowerReturnValue&);
 };
 
 template<typename Derived>
@@ -524,7 +522,6 @@ class MatrixComplexPowerReturnValue : public ReturnByValue< MatrixComplexPowerRe
   private:
     const Derived& m_A;
     const ComplexScalar m_p;
-    MatrixComplexPowerReturnValue& operator=(const MatrixComplexPowerReturnValue&);
 };
 
 namespace internal {
diff --git a/unsupported/Eigen/src/MatrixFunctions/MatrixSquareRoot.h b/unsupported/Eigen/src/MatrixFunctions/MatrixSquareRoot.h
index f3bcef409..c405bfd61 100644
--- a/unsupported/Eigen/src/MatrixFunctions/MatrixSquareRoot.h
+++ b/unsupported/Eigen/src/MatrixFunctions/MatrixSquareRoot.h
@@ -442,8 +442,6 @@ template<typename Derived> class MatrixSquareRootReturnValue
 
   protected:
     const Derived& m_src;
-  private:
-    MatrixSquareRootReturnValue& operator=(const MatrixSquareRootReturnValue&);
 };
 
 namespace internal {