diff --git a/moulinette/utils/text.py b/moulinette/utils/text.py
index 2da101a5..edaa4d24 100644
--- a/moulinette/utils/text.py
+++ b/moulinette/utils/text.py
@@ -65,6 +65,6 @@ def prependlines(text, prepend):
 # Randomize ------------------------------------------------------------
 
 
-def random_ascii(length=20):
+def random_ascii(length=40):
     """Return a random ascii string"""
-    return binascii.hexlify(os.urandom(length)).decode("ascii")
+    return binascii.hexlify(os.urandom(length)).decode("ascii")[:length]
diff --git a/test/test_text.py b/test/test_text.py
index 1bf1f896..4c31f292 100644
--- a/test/test_text.py
+++ b/test/test_text.py
@@ -20,3 +20,4 @@ def test_prependlines():
 
 def test_random_ascii():
     assert isinstance(random_ascii(length=2), str)
+    assert len(random_ascii(length=10)) == 10