diff --git a/tests/utils.cpp b/tests/utils.cpp
new file mode 100644
index 0000000..62e4c23
--- /dev/null
+++ b/tests/utils.cpp
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2018 CESNET, https://photonics.cesnet.cz/
+ * Copyright (C) 2018 FIT CVUT, https://fit.cvut.cz/
+ *
+ * Written by Václav Kubernát <kubervac@fit.cvut.cz>
+ *
+*/
+
+#include "trompeloeil_catch.h"
+#include "utils.hpp"
+
+TEST_CASE("utils")
+{
+    SECTION("filterAndErasePrefix")
+    {
+        std::set<std::string> set{"ahoj", "coze", "copak", "aha", "polivka"};
+
+        REQUIRE((filterAndErasePrefix(set, "a") == std::set<std::string>{"hoj", "ha"}));
+        REQUIRE((filterAndErasePrefix(set, "ah") == std::set<std::string>{"oj", "a"}));
+        REQUIRE((filterAndErasePrefix(set, "aho") == std::set<std::string>{"j"}));
+        REQUIRE((filterAndErasePrefix(set, "polivka") == std::set<std::string>{""}));
+        REQUIRE((filterAndErasePrefix(set, "polivka") == std::set<std::string>{""}));
+        REQUIRE((filterAndErasePrefix(set, "polivkax") == std::set<std::string>{}));
+        REQUIRE((filterAndErasePrefix(set, "co") == std::set<std::string>{"pak", "ze"}));
+    }
+
+}