diff --git a/src/OpenFOAM/primitives/one/oneI.H b/src/OpenFOAM/primitives/one/oneI.H
index 5be4bc3f88..de5a67b89a 100644
--- a/src/OpenFOAM/primitives/one/oneI.H
+++ b/src/OpenFOAM/primitives/one/oneI.H
@@ -42,25 +42,25 @@ public:
 };
 
 template<class Type>
-inline const Type& operator+(const Type& t, const one&)
+inline Type operator+(const Type& t, const one&)
 {
     return t + 1;
 }
 
 template<class Type>
-inline const Type& operator+(const one&, const Type& t)
+inline Type operator+(const one&, const Type& t)
 {
     return 1 + t;
 }
 
 template<class Type>
-inline const Type& operator-(const Type& t, const one&)
+inline Type operator-(const Type& t, const one&)
 {
     return t - 1;
 }
 
 template<class Type>
-inline const Type& operator-(const one&, const Type& t)
+inline Type operator-(const one&, const Type& t)
 {
     return 1 - t;
 }