diff --git a/Eigen/src/Core/Block.h b/Eigen/src/Core/Block.h
index 7f422aa5c..004591aca 100644
--- a/Eigen/src/Core/Block.h
+++ b/Eigen/src/Core/Block.h
@@ -222,7 +222,7 @@ class Block<MatrixType,BlockRows,BlockCols,PacketAccess,HasDirectAccess>
 
     class InnerIterator;
     typedef typename ei_traits<Block>::AlignedDerivedType AlignedDerivedType;
-    friend class Block<MatrixType,BlockRows,BlockCols,PacketAccess==AsRequested?ForceAligned:AsRequested,HasDirectAccess>;
+    friend class Block<MatrixType,BlockRows,BlockCols,PacketAccess==int(AsRequested)?ForceAligned:AsRequested,HasDirectAccess>;
 
     EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Block)