diff --git a/src/bisection-example-flexible.cc b/src/bisection-example-flexible.cc
index 1ca0347fdcbf22a5c5ee9f3a41f0fd0e212ced34..06d612a9bdd26cd1b08f523471da4b7b22580351 100644
--- a/src/bisection-example-flexible.cc
+++ b/src/bisection-example-flexible.cc
@@ -208,7 +208,7 @@ void testTrivialFunction() {
   start *= 17;
   SampleFunctional::SmallVector correction = J.minimise(start, 20);
   assert(J(start + correction) <= J(start));
-  assert(std::abs(J(start + correction) + 0.833333) < 1e-6);
+  assert(std::abs(J(start + correction) + 0.83333333) < 1e-8);
   std::cout << J(start + correction) << std::endl;
 }