diff --git a/src/sdk/sdk_compat.h b/src/sdk/sdk_compat.h
new file mode 100644
index 0000000..8b91bdb
--- /dev/null
+++ b/src/sdk/sdk_compat.h
@@ -0,0 +1,37 @@
+/* Copyright 2017 Cedric Mesnil <cslashm@gmail.com>, Ledger SAS
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SDK_COMPAT_H
+#define SDK_COMPAT_H
+
+#include "bolos_target.h"
+
+#if TARGET_ID == 0x31100004
+//Use original naming of NanoS 1.5.5
+
+#elif TARGET_ID == 0x33000004
+#include "os_io_usb.h"
+// from NanoX 1.2.4 remap G_io_apdu_xx
+#define G_io_apdu_state       G_io_app.apdu_state
+#define G_io_apdu_length      G_io_app.apdu_length
+#define G_io_apdu_state       G_io_app.apdu_state
+
+
+#else
+//Unknown
+#error Target Not Supported
+#endif
+
+#endif
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