diff --git a/tests/hwsim/test_ap_eap.py b/tests/hwsim/test_ap_eap.py
index c9d80c9d3..7e1806563 100644
--- a/tests/hwsim/test_ap_eap.py
+++ b/tests/hwsim/test_ap_eap.py
@@ -5147,7 +5147,7 @@ def test_ap_wpa2_eap_too_many_roundtrips(dev, apdev):
                    wait_connect=False, scan_freq="2412", ieee80211w="1",
                    anonymous_identity="ttls", password="password",
                    ca_cert="auth_serv/ca.pem", phase2="auth=MSCHAP",
-                   fragment_size="8")
+                   fragment_size="4")
     ev = dev[0].wait_event(["EAP: more than",
                             "CTRL-EVENT-EAP-SUCCESS"], timeout=20)
     if ev is None or "EAP: more than" not in ev: