diff --git a/tests/test_RapidPeptidesGenerator.py b/tests/test_RapidPeptidesGenerator.py
index 5f018b43e9cfe2f63120f3b408eff7c35056371b..335305e4bddb6435b282aca6e630025926a6c1e1 100644
--- a/tests/test_RapidPeptidesGenerator.py
+++ b/tests/test_RapidPeptidesGenerator.py
@@ -45,6 +45,24 @@ def test_restricted_enzyme_id(capsys):
     # Normal test
     assert RapidPeptidesGenerator.restricted_enzyme_id("asp-n") == "asp-n"
 
+def test_restricted_int(capsys):
+    """Test function 'restricted_int(mc_val)'"""
+    # Error test
+    with pytest.raises(SystemExit) as pytest_wrapped_e:
+        RapidPeptidesGenerator.restricted_int(-10)
+    _, err = capsys.readouterr()
+    assert err == "Value Error: miscleavage value should be greater then 0.\n"
+    assert pytest_wrapped_e.type == SystemExit
+    assert pytest_wrapped_e.value.code == 1
+    with pytest.raises(SystemExit) as pytest_wrapped_e:
+        RapidPeptidesGenerator.restricted_int("z")
+    _, err = capsys.readouterr()
+    assert err == "Type Error: miscleavage value should be an integer.\n"
+    assert pytest_wrapped_e.type == SystemExit
+    assert pytest_wrapped_e.value.code == 1
+    # Normal test
+    assert RapidPeptidesGenerator.restricted_int(3) == 3
+
 def test_list_enzyme(capsys):
     """Test function 'list_enzyme()'
     This test should be run with empty user file