diff --git a/dune/istl/paamg/aggregates.hh b/dune/istl/paamg/aggregates.hh
index 6b657d045cb52d701afb569a801611d32b4c779d..67a7886c716a1250ff46e15e001b0993e2840eca 100644
--- a/dune/istl/paamg/aggregates.hh
+++ b/dune/istl/paamg/aggregates.hh
@@ -406,7 +406,7 @@ namespace Dune
       template<typename T>
       T csgn(const T & v)
       {
-        return (T(0) < val) - (val < T(0));
+        return (T(0) < v) - (v < T(0));
       }
 
       //! sign function for complex numbers