diff --git a/examples/curve-pot.py b/examples/curve-pot.py
index 777c53eeac9dfaf7413cf896d19f782882957cbe..9d8678f5e6d962c5656fa572c06d48b3a167a932 100644
--- a/examples/curve-pot.py
+++ b/examples/curve-pot.py
@@ -199,6 +199,10 @@ def draw_pot_figure(aspect_ratio,
 
         # }}}
 
+    fp.write_vtk_file("potential.vts", [
+        ("potential", vol_pot.real)
+        ])
+
     if 0:
         # {{{ 2D false-color plot
 
diff --git a/sumpy/p2p.py b/sumpy/p2p.py
index 0345f9046c1e97a43b59cc84076ae63c886b2bc9..7234180f62ff12d63b2e7c5afdaeaecf12c93f87 100644
--- a/sumpy/p2p.py
+++ b/sumpy/p2p.py
@@ -154,8 +154,8 @@ class P2P(P2PBase):
                         shape=(self.dim, "nsources")),
                     lp.GlobalArg("targets", None,
                         shape=(self.dim, "ntargets")),
-                    lp.ValueArg("nsources", np.int32),
-                    lp.ValueArg("ntargets", np.int32),
+                    lp.ValueArg("nsources", None),
+                    lp.ValueArg("ntargets", None),
                     lp.GlobalArg("strength", None, shape="nstrengths,nsources"),
                     lp.GlobalArg("result", None,
                         shape="nresults,ntargets", dim_tags="sep,C")
diff --git a/sumpy/qbx.py b/sumpy/qbx.py
index 629f9092bb88a564a0c822d1f844a9326ddbab49..0b3dc03537e788a75412b712e1c3ad18b14c11db 100644
--- a/sumpy/qbx.py
+++ b/sumpy/qbx.py
@@ -111,8 +111,8 @@ class LayerPotentialBase(KernelComputation, KernelCacheWrapper):
                     shape=(self.dim, "ntargets"), order="C"),
                 lp.GlobalArg("center", None,
                     shape=(self.dim, "ntargets"), order="C"),
-                lp.ValueArg("nsources", np.int32),
-                lp.ValueArg("ntargets", np.int32),
+                lp.ValueArg("nsources", None),
+                lp.ValueArg("ntargets", None),
                 ]
 
     @memoize_method