diff --git a/examples/xml/custom_source/source_ring.cpp b/examples/xml/custom_source/source_ring.cpp
index ef2784ea36..fb361d1aa9 100644
--- a/examples/xml/custom_source/source_ring.cpp
+++ b/examples/xml/custom_source/source_ring.cpp
@@ -12,14 +12,14 @@ extern "C" openmc::Particle::Bank sample_source() {
     particle.wgt = 1.0;
     // position
     
-    double angle = 2.*M_PI*openmc::prn();
+    double angle = 2. * M_PI * openmc::prn();
     double radius = 3.0;
-    particle.r.x = radius*std::cos(angle);
-    particle.r.y = radius*std::sin(angle);
-    particle.r.z = 0.;
+    particle.r.x = radius * std::cos(angle);
+    particle.r.y = radius * std::sin(angle);
+    particle.r.z = 0.0;
     // angle
-    particle.u = {1.,0,0};
+    particle.u = {1.0, 0.0, 0.0};
     particle.E = 14.08e6;
     particle.delayed_group = 0;
     return particle;    
-}
\ No newline at end of file
+}