diff --git a/test/poisson/poisson_dg.ufl b/test/poisson/poisson_dg.ufl
index 06f3eb0f953695ccb9bf948fa947080901956e97..0653a89cf5a7eb4d0a3ec8a6e44df485ec2d53bb 100644
--- a/test/poisson/poisson_dg.ufl
+++ b/test/poisson/poisson_dg.ufl
@@ -13,7 +13,7 @@ v = TestFunction(V)
 n = FacetNormal(cell)('+')
 
 gamma = 1.0
-theta = 1.0
+theta = -1.0
 
 r = inner(grad(u), grad(v))*dx \
   + inner(n, avg(grad(u)))*jump(v)*dS \