diff --git a/Code/CryEngine/CryCommon/ISystem.h b/Code/CryEngine/CryCommon/ISystem.h
index 67128ef7d7..1a2ffc5a7c 100644
--- a/Code/CryEngine/CryCommon/ISystem.h
+++ b/Code/CryEngine/CryCommon/ISystem.h
@@ -1149,13 +1149,13 @@ 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;