diff --git a/examples/bubble/periodic_jet_levelset.py b/examples/bubble/periodic_jet_levelset.py
index 9e183b5abe600b81e73dd22aa06ee9311bcb49f7..bbb1cfe1dba86b8c9d188148cd03045fc2d5061f 100644
--- a/examples/bubble/periodic_jet_levelset.py
+++ b/examples/bubble/periodic_jet_levelset.py
@@ -24,7 +24,7 @@ def init_phi(data, coords, L):
     Di = np.empty_like(phi)
     X,Y    = coords 
     Ly, Lx = L
-    R = Lx/16*(2.5 - 0.75*np.sin(2*np.pi*Y))
+    R = Lx*(0.15 - 0.05*np.sin(2*np.pi*Y))
     Di[...] = (X-0.5*Lx)**2 - R**2
     mask = (np.abs(Di)<np.abs(phi))
     phi[mask] = Di[mask]