diff --git a/Code/CryEngine/CryCommon/ISystem.h b/Code/CryEngine/CryCommon/ISystem.h
index 653776f55b..bb4c320439 100644
--- a/Code/CryEngine/CryCommon/ISystem.h
+++ b/Code/CryEngine/CryCommon/ISystem.h
@@ -1154,13 +1154,13 @@ struct DiskOperationInfo
         return *this;
     }
 
-    DiskOperationInfo& operator - (const DiskOperationInfo& rv)
+    DiskOperationInfo operator - (const DiskOperationInfo& rv)
     {
         DiskOperationInfo res(*this);
         return res -= rv;
     }
 
-    DiskOperationInfo& operator + (const DiskOperationInfo& rv)
+    DiskOperationInfo operator + (const DiskOperationInfo& rv)
     {
         DiskOperationInfo res(*this);
         return res += rv;