diff --git a/dune/solvers/iterationsteps/blockgssteps.hh b/dune/solvers/iterationsteps/blockgssteps.hh
index 76cae5f91eeab69d4c6ebf86a4327d472227cfe5..eec9dde1090b82dea4becdcbe75e4ceab4c53de5 100644
--- a/dune/solvers/iterationsteps/blockgssteps.hh
+++ b/dune/solvers/iterationsteps/blockgssteps.hh
@@ -208,7 +208,9 @@ auto truncateSymmetrically(LinearSolver&& linearSolver) {
 
 namespace LocalSolverRegularizer {
 
-static constexpr double defaultDiagRegularizeParameter = 1e-10;
+// a suitable value for defaultDiagRagularization could be 1e-10
+// nevertheless, the default is 0 to avoid unintentional regularization
+static constexpr double defaultDiagRegularizeParameter = 0;
 
 // Note: move-capture, auto-return and auto-lambda-arguments require C++14
 /**