diff --git a/tests/test_fns.py b/tests/test_fns.py
index 5809461..9a9c712 100644
--- a/tests/test_fns.py
+++ b/tests/test_fns.py
@@ -34,6 +34,13 @@ def test_odd():
     assert not c.is_odd(-2)
 
 
+def test_comp_no_fn():
+    fn = c.comp()
+    assert fn() is None
+    assert fn(42) is None
+    assert fn("Hello, world!") is None
+
+
 def test_comp():
     def twice(n):
         return n * 2
diff --git a/tests/test_seqs.py b/tests/test_seqs.py
index 010e752..3b6c28c 100644
--- a/tests/test_seqs.py
+++ b/tests/test_seqs.py
@@ -1,6 +1,6 @@
 import re
 from collections import OrderedDict, Counter, deque, defaultdict
-from typing import Iterable, Any
+from typing import Iterable, Any, cast
 
 import pytest
 
@@ -145,6 +145,7 @@ def test_rest():
 
 def test_drop():
     assert c.drop(10, infinite_range_fn()) is not None
+    assert list(c.drop(10, cast(Iterable, None))) == []
     assert list(c.drop(0, [])) == []
     assert list(c.drop(1000, [])) == []
     assert list(c.drop(1000, [1, 2, 3, 4])) == []
@@ -445,11 +446,21 @@ def add_el():
         els.append(42)
 
     c.dorun(c.take(3, c.repeatedly(add_el)))
-    assert els == [42, 42, 42]
+    assert els == [42] * 3
 
     els = []
     c.dorun(c.repeatedly(add_el, 2))
-    assert els == [42, 42]
+    assert els == [42] * 2
+
+
+def test_repeatedly_nf():
+    els = []
+
+    def add_el():
+        els.append(42)
+
+    c.dorun(c.repeatedly(3, add_el))
+    assert els == [42] * 3
 
 
 def test_iterate():