diff --git a/unittest.cpp b/unittest.cpp
index 0acaa65..851208c 100644
--- a/unittest.cpp
+++ b/unittest.cpp
@@ -26,3 +26,19 @@ TEST_CASE("same elements"){
     CHECK(min == max);
     CHECK(max == min);
 }
+
+TEST_CASE("only one number"){
+    double min = 0;
+    double max = 0;
+    find_minmax({1}, min, max);
+    CHECK(min == 1);
+    CHECK(max == 1);
+}
+
+TEST_CASE("distinct negative numbers") {
+    double min = 0;
+    double max = 0;
+    find_minmax({0, -2}, min, max);
+    CHECK(min == -2);
+    CHECK(max == 0);
+}