diff --git a/tests/assertion_tests.cpp b/tests/assertion_tests.cpp
new file mode 100644
index 0000000..25c0089
--- /dev/null
+++ b/tests/assertion_tests.cpp
@@ -0,0 +1,46 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
+//
+// This code is licensed under the MIT License (MIT).
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include <catch/catch.hpp> // for AssertionHandler, StringRef, CHECK, CHECK...
+
+#include <gsl/gsl_assert> // for fail_fast (ptr only), Ensures, Expects
+
+using namespace gsl;
+
+int f(int i)
+{
+    Expects(i > 0 && i < 10);
+    return i;
+}
+
+TEST_CASE("expects")
+{
+    CHECK(f(2) == 2);
+    CHECK_THROWS_AS(f(10), fail_fast);
+}
+
+int g(int i)
+{
+    i++;
+    Ensures(i > 0 && i < 10);
+    return i;
+}
+
+TEST_CASE("ensures")
+{
+    CHECK(g(2) == 3);
+    CHECK_THROWS_AS(g(9), fail_fast);
+}