diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 4adb29d160..9d7625786f 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -194,6 +194,7 @@ test-suite special_fun :
    [ run git_issue_1139.cpp ]
    [ run git_issue_1175.cpp ]
    [ run git_issue_1194.cpp ]
+   [ run git_issue_1203.cpp ]
    [ run special_functions_test.cpp /boost/test//boost_unit_test_framework  ]
    [ run test_airy.cpp test_instances//test_instances pch_light /boost/test//boost_unit_test_framework  ]
    [ run test_bessel_j.cpp test_instances//test_instances pch_light /boost/test//boost_unit_test_framework  ]
diff --git a/test/git_issue_1203.cpp b/test/git_issue_1203.cpp
new file mode 100644
index 0000000000..76004294ef
--- /dev/null
+++ b/test/git_issue_1203.cpp
@@ -0,0 +1,48 @@
+//  (C) Copyright Matt Borland 2024.
+//  Use, modification and distribution are subject to the
+//  Boost Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See: https://github.com/boostorg/math/issues/1203
+
+#include "math_unit_test.hpp"
+#include <boost/math/distributions/poisson.hpp>
+
+int main()
+{
+    constexpr auto mean = 2719.3;
+
+    const auto dist = boost::math::poisson_distribution<>(mean);
+
+    // Generated from: Quantile[PoissonDistribution[2719.13], p]
+
+    // Passing before issue (p >= .50):
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.54), 2724.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.53), 2723.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.52), 2722.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.51), 2720.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.50), 2719.0, 10);
+
+    // Failing before issue (p < .50):
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.49), 2718.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.48), 2716.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.47), 2715.0, 10);
+
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.04), 2628.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.03), 2621.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.02), 2613.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist, 0.01), 2599.0, 10);
+
+    // Check with smaller mean
+    constexpr auto mean_2 = 12.0;
+    const auto dist_2 = boost::math::poisson_distribution<>(mean_2);
+
+    CHECK_ULP_CLOSE(boost::math::quantile(dist_2, 0.54), 12.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist_2, 0.53), 12.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist_2, 0.52), 12.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist_2, 0.40), 11.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist_2, 0.30), 10.0, 10);
+    CHECK_ULP_CLOSE(boost::math::quantile(dist_2, 0.20), 09.0, 10);
+
+    return boost::math::test::report_errors();
+}