diff --git a/test-data/samples/generators.py b/test-data/samples/generators.py
index 9150c96c8276..eb6d70104144 100644
--- a/test-data/samples/generators.py
+++ b/test-data/samples/generators.py
@@ -6,7 +6,7 @@
 
 def iter_primes() -> Iterator[int]:
     # an iterator of all numbers between 2 and +infinity
-    numbers = itertools.count(2)
+    numbers: Iterator[int] = itertools.count(2)
 
     # generate primes forever
     while True: