diff --git a/Lab01.cbp b/Lab01.cbp
index 30cb1a9..5d67df3 100644
--- a/Lab01.cbp
+++ b/Lab01.cbp
@@ -38,6 +38,7 @@
 		<Unit filename="main.cpp" />
 		<Unit filename="text.cpp" />
 		<Unit filename="text.h" />
+		<Unit filename="unittest.cbp" />
 		<Extensions />
 	</Project>
 </CodeBlocks_project_file>
diff --git a/doctest.h b/doctest.h
index 5c754cd..6f43ce0 100644
--- a/doctest.h
+++ b/doctest.h
@@ -7104,3 +7104,4 @@ DOCTEST_SUPPRESS_COMMON_WARNINGS_POP
 #undef NOMINMAX
 #undef DOCTEST_UNDEF_NOMINMAX
 #endif // DOCTEST_UNDEF_NOMINMAX
+
diff --git a/unittest.cbp b/unittest.cbp
index d291579..379d0a2 100644
--- a/unittest.cbp
+++ b/unittest.cbp
@@ -31,6 +31,7 @@
 		<Compiler>
 			<Add option="-Wall" />
 		</Compiler>
+		<Unit filename="doctest.h" />
 		<Unit filename="histogram.cpp" />
 		<Unit filename="histogram_internal.h" />
 		<Unit filename="unittest.cpp" />
diff --git a/unittest.cpp b/unittest.cpp
index e69de29..a9ba7e5 100644
--- a/unittest.cpp
+++ b/unittest.cpp
@@ -0,0 +1,12 @@
+#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);
+}