diff --git a/autotests/testEAP-PEAP/IWD-Frag/main.conf b/autotests/testEAP-PEAP/IWD-Frag/main.conf
index bdc86869..e583733c 100644
--- a/autotests/testEAP-PEAP/IWD-Frag/main.conf
+++ b/autotests/testEAP-PEAP/IWD-Frag/main.conf
@@ -1,2 +1,2 @@
 [EAP]
-mtu=100
+MTU=100
diff --git a/autotests/testEAP-PWD/IWD-Frag/main.conf b/autotests/testEAP-PWD/IWD-Frag/main.conf
index 50ab0f56..161764bf 100644
--- a/autotests/testEAP-PWD/IWD-Frag/main.conf
+++ b/autotests/testEAP-PWD/IWD-Frag/main.conf
@@ -1,2 +1,2 @@
 [EAP]
-mtu=40
+MTU=40
diff --git a/autotests/testEAP-TLS-Frag/main.conf b/autotests/testEAP-TLS-Frag/main.conf
index bdc86869..e583733c 100644
--- a/autotests/testEAP-TLS-Frag/main.conf
+++ b/autotests/testEAP-TLS-Frag/main.conf
@@ -1,2 +1,2 @@
 [EAP]
-mtu=100
+MTU=100
diff --git a/autotests/testEAP-TTLS-Frag/main.conf b/autotests/testEAP-TTLS-Frag/main.conf
index bdc86869..e583733c 100644
--- a/autotests/testEAP-TTLS-Frag/main.conf
+++ b/autotests/testEAP-TTLS-Frag/main.conf
@@ -1,2 +1,2 @@
 [EAP]
-mtu=100
+MTU=100
diff --git a/autotests/testEAP-WPS-Frag/main.conf b/autotests/testEAP-WPS-Frag/main.conf
index bdc86869..e583733c 100644
--- a/autotests/testEAP-WPS-Frag/main.conf
+++ b/autotests/testEAP-WPS-Frag/main.conf
@@ -1,2 +1,2 @@
 [EAP]
-mtu=100
+MTU=100
diff --git a/src/eap.c b/src/eap.c
index 23868811..c083a5df 100644
--- a/src/eap.c
+++ b/src/eap.c
@@ -679,7 +679,7 @@ int eap_unregister_method(struct eap_method *method)
 
 void __eap_set_config(struct l_settings *config)
 {
-	if (!l_settings_get_uint(config, "EAP", "mtu", &default_mtu))
+	if (!l_settings_get_uint(config, "EAP", "MTU", &default_mtu))
 		default_mtu = 1400; /* on WiFi the real MTU is around 2304 */
 }