diff --git a/src/avalanche/friction/Voellmy/Voellmy.C b/src/avalanche/friction/Voellmy/Voellmy.C
index 8c9292a21053d27c05a350a6b6ddea7d6331740d..533c5ff9a69e97ff95af78078222962d987dd266 100644
--- a/src/avalanche/friction/Voellmy/Voellmy.C
+++ b/src/avalanche/friction/Voellmy/Voellmy.C
@@ -53,7 +53,7 @@ Foam::frictionModels::Voellmy::Voellmy
 :
     frictionModel(type(), frictionProperties, Us, h, p),
     mu_("mu", dimless, coeffDict_),
-    xi_("xi", dimless, coeffDict_)
+    xi_("xi", dimAcceleration, coeffDict_)
 {
     Info<< "    " << mu_ << nl
         << "    " << xi_ << nl << endl;