diff --git a/unittest.cpp b/unittest.cpp
index a9ba7e5..10c5e28 100644
--- a/unittest.cpp
+++ b/unittest.cpp
@@ -1,12 +1,25 @@
-#define DOCTEST_CONFIG_NO_MULTITHREADING
 #define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
 #include "doctest.h"
 #include "histogram_internal.h"
 
-TEST_CASE("distinct positive numbers") {
-    double min = 0;
-    double max = 0;
-    find_minmax({1, 2}, min, max);
-    CHECK(min == 1);
-    CHECK(max == 2);
+TEST_CASE("Test find_minmax") {
+    double min, max;
+
+    SUBCASE("Empty vector") {
+        find_minmax({}, min, max);
+        CHECK(min == 0);
+        CHECK(max == 0);
+    }
+
+    SUBCASE("Single element") {
+        find_minmax({5}, min, max);
+        CHECK(min == 5);
+        CHECK(max == 5);
+    }
+
+    SUBCASE("Positive numbers") {
+        find_minmax({1, 2, 3}, min, max);
+        CHECK(min == 1);
+        CHECK(max == 3);
+    }
 }