diff --git a/libs/lpac-jni/src/main/java/net/typeblog/lpac_jni/ProfileDiscoveryCallback.kt b/libs/lpac-jni/src/main/java/net/typeblog/lpac_jni/ProfileDiscoveryCallback.kt
index d51eb74..b70e0d8 100644
--- a/libs/lpac-jni/src/main/java/net/typeblog/lpac_jni/ProfileDiscoveryCallback.kt
+++ b/libs/lpac-jni/src/main/java/net/typeblog/lpac_jni/ProfileDiscoveryCallback.kt
@@ -1,5 +1,5 @@
 package net.typeblog.lpac_jni
 
 interface ProfileDiscoveryCallback {
-    fun onDiscovered(servers: Set<String>)
+    fun onDiscovered(servers: List<String>)
 }
diff --git a/libs/lpac-jni/src/main/jni/lpac-jni/interface-wrapper.c b/libs/lpac-jni/src/main/jni/lpac-jni/interface-wrapper.c
index 3f2dff1..be490fd 100644
--- a/libs/lpac-jni/src/main/jni/lpac-jni/interface-wrapper.c
+++ b/libs/lpac-jni/src/main/jni/lpac-jni/interface-wrapper.c
@@ -1,7 +1,7 @@
 #include <string.h>
 #include <malloc.h>
 #include "interface-wrapper.h"
-#include "lpac-convertor.h"
+#include "utils.h"
 
 static jmethodID method_apdu_connect;
 static jmethodID method_apdu_disconnect;
@@ -95,15 +95,7 @@ http_interface_transmit(struct euicc_ctx *ctx, const char *url, uint32_t *rcode,
     jbyteArray txArr = (*env)->NewByteArray(env, (jsize) tx_len);
     (*env)->SetByteArrayRegion(env, txArr, 0, (jsize) tx_len, (const jbyte *) tx);
 
-    jobject header_list = new_array_list(env);
-    jclass header_list_class = (*env)->GetObjectClass(env, header_list);
-    jmethodID add_header = (*env)->GetMethodID(env, header_list_class, "add", "(Ljava/lang/Object;)Z");
-
-    for (int i = 0; headers[i] != NULL; i++) {
-        jstring header = toJString(env, headers[i]);
-        (*env)->CallBooleanMethod(env, header_list, add_header, header);
-        (*env)->DeleteLocalRef(env, header);
-    }
+    jobject header_list = to_string_list(env, (char **) headers);
 
     jobject ret = (*env)->CallObjectMethod(env, LPAC_JNI_CTX(ctx)->http_interface,
                                            method_http_transmit, jurl, txArr, header_list);
diff --git a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-discovery.c b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-discovery.c
index 446521b..e2246fc 100644
--- a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-discovery.c
+++ b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-discovery.c
@@ -4,7 +4,7 @@
 #include <string.h>
 #include <malloc.h>
 #include <syslog.h>
-#include "lpac-convertor.h"
+#include "utils.h"
 #include "lpac-discovery.h"
 
 JNIEXPORT jobject JNICALL
@@ -52,7 +52,7 @@ Java_net_typeblog_lpac_1jni_LpacJni_discoveryProfile(
 
     jclass callback_class = (*env)->GetObjectClass(env, callback);
     jmethodID on_discovered = (*env)->GetMethodID(env, callback_class, "onDiscovered",
-                                                  "(Ljava/util/Set;)V");
+                                                  "(Ljava/util/List;)V");
 
     const char *_address = (*env)->GetStringUTFChars(env, address, NULL);
     const char *_imei = NULL;
@@ -95,7 +95,7 @@ Java_net_typeblog_lpac_1jni_LpacJni_discoveryProfile(
         goto out;
     }
 
-    (*env)->CallVoidMethod(env, callback, on_discovered, to_string_set(env, smdp_list));
+    (*env)->CallVoidMethod(env, callback, on_discovered, to_string_list(env, smdp_list));
 
     out:
 
diff --git a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-download.c b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-download.c
index e069383..b1ab73e 100644
--- a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-download.c
+++ b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-download.c
@@ -3,7 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <syslog.h>
-#include "lpac-convertor.h"
+#include "utils.h"
 #include "lpac-download.h"
 
 static jobject download_state_preparing;
diff --git a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-jni.c b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-jni.c
index 0b6b496..9196ff7 100644
--- a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-jni.c
+++ b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-jni.c
@@ -9,7 +9,7 @@
 #include "lpac-download.h"
 #include "lpac-notifications.h"
 #include "lpac-discovery.h"
-#include "lpac-convertor.h"
+#include "utils.h"
 #include "interface-wrapper.h"
 
 JavaVM *jvm = NULL;
diff --git a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-notifications.c b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-notifications.c
index e6c0069..a581d40 100644
--- a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-notifications.c
+++ b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-notifications.c
@@ -2,7 +2,7 @@
 #include <euicc/es10b.h>
 #include <malloc.h>
 #include <syslog.h>
-#include "lpac-convertor.h"
+#include "utils.h"
 #include "lpac-notifications.h"
 
 JNIEXPORT jobject JNICALL
diff --git a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-convertor.c b/libs/lpac-jni/src/main/jni/lpac-jni/utils.c
similarity index 92%
rename from libs/lpac-jni/src/main/jni/lpac-jni/lpac-convertor.c
rename to libs/lpac-jni/src/main/jni/lpac-jni/utils.c
index da714ac..542ccc4 100644
--- a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-convertor.c
+++ b/libs/lpac-jni/src/main/jni/lpac-jni/utils.c
@@ -1,4 +1,4 @@
-#include "lpac-convertor.h"
+#include "utils.h"
 #include <malloc.h>
 #include <string.h>
 #include <syslog.h>
@@ -145,6 +145,19 @@ jobject to_string_set(JNIEnv *env, char **values) {
     return elements;
 }
 
+jobject to_string_list(JNIEnv *env, char **values) {
+    jclass set_class = (*env)->FindClass(env, ARRAY_LIST_CLASS);
+    jmethodID set_constructor = (*env)->GetMethodID(env, set_class, "<init>", "()V");
+    jobject elements = (*env)->NewObject(env, set_class, set_constructor);
+    jmethodID add_element = (*env)->GetMethodID(env, set_class, "add", "(Ljava/lang/Object;)Z");
+    jstring element = NULL;
+    for (jsize index = 0; values[index] != NULL; index++) {
+        element = toJString(env, values[index]);
+        (*env)->CallBooleanMethod(env, elements, add_element, element);
+    }
+    return elements;
+}
+
 jobject build_profile_metadata(JNIEnv *env, struct es8p_metadata *metadata) {
     if (metadata == NULL) return NULL;
 
diff --git a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-convertor.h b/libs/lpac-jni/src/main/jni/lpac-jni/utils.h
similarity index 96%
rename from libs/lpac-jni/src/main/jni/lpac-jni/lpac-convertor.h
rename to libs/lpac-jni/src/main/jni/lpac-jni/utils.h
index cc7c568..617f5f4 100644
--- a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-convertor.h
+++ b/libs/lpac-jni/src/main/jni/lpac-jni/utils.h
@@ -31,6 +31,8 @@ jobject to_version(JNIEnv *env, const char *version);
 
 jobject to_string_set(JNIEnv *env, char **values);
 
+jobject to_string_list(JNIEnv *env, char **values);
+
 jobject build_profile_metadata(JNIEnv *env, struct es8p_metadata *metadata);
 
 jobject to_profile_management_operation(enum es10b_profile_management_operation operation);