diff --git a/bench/cec2020/benchFunctions_test.go b/bench/cec2020/benchFunctions_test.go
new file mode 100644
index 0000000..2f474e5
--- /dev/null
+++ b/bench/cec2020/benchFunctions_test.go
@@ -0,0 +1,50 @@
+// Copyright 2023 wanderer <a_mirre at utb dot cz>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package cec2020
+
+import "testing"
+
+func TestComposition1(t *testing.T) {
+	in := []float64{-9.2, 10, .7, 3, -80.2843}
+	want := 7248.007126969505
+
+	got := Composition1(in)
+
+	if got != want {
+		t.Errorf("unexpected result from Composition1, want: %f, got: %v", want, got)
+	}
+}
+
+func TestComposition2(t *testing.T) {
+	in := []float64{-9.2, 10, .7, 3, -80.2843}
+	want := 2.0384259701506793e+08
+
+	got := Composition2(in)
+
+	if got != want {
+		t.Errorf("unexpected result from Composition2, want: %f, got: %v", want, got)
+	}
+}
+
+func TestComposition3(t *testing.T) {
+	in := []float64{-9.2, 10, .7, 3, -80.2843}
+	want := 8.699499674241544e+07
+
+	got := Composition3(in)
+
+	if got != want {
+		t.Errorf("unexpected result from Composition3, want: %f, got: %v", want, got)
+	}
+}
+
+func TestGriewank(t *testing.T) {
+	in := []float64{-9.2, 10, .7, 3, -80.2843}
+	want := 2.6599247066225002
+
+	got := Griewank(in)
+
+	if got != want {
+		t.Errorf("unexpected result from Griewank, want: %f, got: %v", want, got)
+	}
+}