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 a61fc96..df27e92 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
@@ -13,8 +13,7 @@ jmethodID method_http_transmit;
 jfieldID field_resp_rcode;
 jfieldID field_resp_data;
 
-void interface_wrapper_init() {
-    LPAC_JNI_SETUP_ENV;
+void interface_wrapper_init(JNIEnv *env) {
     jclass apdu_class = (*env)->FindClass(env, "net/typeblog/lpac_jni/ApduInterface");
     method_apdu_connect = (*env)->GetMethodID(env, apdu_class, "connect", "()V");
     method_apdu_disconnect = (*env)->GetMethodID(env, apdu_class, "disconnect", "()V");
diff --git a/libs/lpac-jni/src/main/jni/lpac-jni/interface-wrapper.h b/libs/lpac-jni/src/main/jni/lpac-jni/interface-wrapper.h
index e22837b..fec3869 100644
--- a/libs/lpac-jni/src/main/jni/lpac-jni/interface-wrapper.h
+++ b/libs/lpac-jni/src/main/jni/lpac-jni/interface-wrapper.h
@@ -5,7 +5,7 @@
 #include <euicc/interface.h>
 #include "lpac-jni.h"
 
-void interface_wrapper_init();
+void interface_wrapper_init(JNIEnv *env);
 
 extern struct euicc_apdu_interface lpac_jni_apdu_interface;
 extern struct euicc_http_interface lpac_jni_http_interface;
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 bae2ee8..33c5b81 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
@@ -13,49 +13,34 @@ jobject download_state_finalizing;
 
 jmethodID on_state_update;
 
-void lpac_download_init() {
-    LPAC_JNI_SETUP_ENV;
+#define DOWNLOAD_CALLBACK_CLASS "net/typeblog/lpac_jni/ProfileDownloadCallback"
+#define DOWNLOAD_STATE_CLASS DOWNLOAD_CALLBACK_CLASS "$DownloadState"
 
-    jclass download_state_class = (*env)->FindClass(env,
-                                                    "net/typeblog/lpac_jni/ProfileDownloadCallback$DownloadState");
-    jfieldID download_state_preparing_field = (*env)->GetStaticFieldID(env, download_state_class,
-                                                                       "Preparing",
-                                                                       "Lnet/typeblog/lpac_jni/ProfileDownloadCallback$DownloadState;");
-    download_state_preparing = (*env)->GetStaticObjectField(env, download_state_class,
-                                                            download_state_preparing_field);
-    download_state_preparing = (*env)->NewGlobalRef(env, download_state_preparing);
-    jfieldID download_state_connecting_field = (*env)->GetStaticFieldID(env, download_state_class,
-                                                                        "Connecting",
-                                                                        "Lnet/typeblog/lpac_jni/ProfileDownloadCallback$DownloadState;");
-    download_state_connecting = (*env)->GetStaticObjectField(env, download_state_class,
-                                                             download_state_connecting_field);
-    download_state_connecting = (*env)->NewGlobalRef(env, download_state_connecting);
-    jfieldID download_state_authenticating_field = (*env)->GetStaticFieldID(env,
-                                                                            download_state_class,
-                                                                            "Authenticating",
-                                                                            "Lnet/typeblog/lpac_jni/ProfileDownloadCallback$DownloadState;");
-    download_state_authenticating = (*env)->GetStaticObjectField(env, download_state_class,
-                                                                 download_state_authenticating_field);
-    download_state_authenticating = (*env)->NewGlobalRef(env, download_state_authenticating);
-    jfieldID download_state_downloading_field = (*env)->GetStaticFieldID(env, download_state_class,
-                                                                         "Downloading",
-                                                                         "Lnet/typeblog/lpac_jni/ProfileDownloadCallback$DownloadState;");
-    download_state_downloading = (*env)->GetStaticObjectField(env, download_state_class,
-                                                              download_state_downloading_field);
-    download_state_downloading = (*env)->NewGlobalRef(env, download_state_downloading);
-    jfieldID download_state_finalizng_field = (*env)->GetStaticFieldID(env, download_state_class,
-                                                                       "Finalizing",
-                                                                       "Lnet/typeblog/lpac_jni/ProfileDownloadCallback$DownloadState;");
-    download_state_finalizing = (*env)->GetStaticObjectField(env, download_state_class,
-                                                             download_state_finalizng_field);
-    download_state_finalizing = (*env)->NewGlobalRef(env, download_state_finalizing);
-
-    jclass download_callback_class = (*env)->FindClass(env,
-                                                       "net/typeblog/lpac_jni/ProfileDownloadCallback");
-    on_state_update = (*env)->GetMethodID(env, download_callback_class, "onStateUpdate",
-                                          "(Lnet/typeblog/lpac_jni/ProfileDownloadCallback$DownloadState;)V");
+static jobject bind_static_field(JNIEnv *env, jclass clazz, const char *name, const char *sig) {
+    jfieldID field = (*env)->GetStaticFieldID(env, clazz, name, sig);
+    jobject bound = (*env)->GetStaticObjectField(env, clazz, field);
+    return (*env)->NewGlobalRef(env, bound);
 }
 
+#define BIND_DOWNLOAD_STATE_STATIC_FIELD(NAME, FIELD) \
+    download_state_##NAME = bind_static_field(env, download_state_class, FIELD, "L" DOWNLOAD_STATE_CLASS ";")
+
+void lpac_download_init(JNIEnv *env) {
+    jclass download_state_class = (*env)->FindClass(env, DOWNLOAD_STATE_CLASS);
+
+    BIND_DOWNLOAD_STATE_STATIC_FIELD(preparing, "Preparing");
+    BIND_DOWNLOAD_STATE_STATIC_FIELD(connecting, "Connecting");
+    BIND_DOWNLOAD_STATE_STATIC_FIELD(authenticating, "Authenticating");
+    BIND_DOWNLOAD_STATE_STATIC_FIELD(downloading, "Downloading");
+    BIND_DOWNLOAD_STATE_STATIC_FIELD(finalizing, "Finalizing");
+
+    jclass download_callback_class = (*env)->FindClass(env, DOWNLOAD_CALLBACK_CLASS);
+    on_state_update = (*env)->GetMethodID(
+            env, download_callback_class, "onStateUpdate", "(L" DOWNLOAD_STATE_CLASS ";)V");
+}
+
+#undef BIND_DOWNLOAD_STATE_STATIC_FIELD
+
 JNIEXPORT jint JNICALL
 Java_net_typeblog_lpac_1jni_LpacJni_downloadProfile(JNIEnv *env, jobject thiz, jlong handle,
                                                     jstring smdp, jstring matching_id,
diff --git a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-download.h b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-download.h
index 7130f52..b68bc99 100644
--- a/libs/lpac-jni/src/main/jni/lpac-jni/lpac-download.h
+++ b/libs/lpac-jni/src/main/jni/lpac-jni/lpac-download.h
@@ -3,4 +3,4 @@
 #include <jni.h>
 #include "lpac-jni.h"
 
-void lpac_download_init();
\ No newline at end of file
+void lpac_download_init(JNIEnv *env);
\ No newline at end of file
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 ca319db..f0aa917 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
@@ -19,10 +19,11 @@ jmethodID string_constructor;
 
 jint JNI_OnLoad(JavaVM *vm, void *reserved) {
     jvm = vm;
-    interface_wrapper_init();
-    lpac_download_init();
-
     LPAC_JNI_SETUP_ENV;
+
+    interface_wrapper_init(env);
+    lpac_download_init(env);
+
     string_class = (*env)->FindClass(env, "java/lang/String");
     string_class = (*env)->NewGlobalRef(env, string_class);
     string_constructor = (*env)->GetMethodID(env, string_class, "<init>",