diff --git a/extra-functions.h b/extra-functions.h
index 83a4318..6d2a085 100644
--- a/extra-functions.h
+++ b/extra-functions.h
@@ -6,7 +6,7 @@
 int __pclose(FILE *iop);
 
 // Device ID variable / function
-char device_id[64];
+extern char device_id[64];
 void get_device_id();
 static char* copy_sideloaded_package(const char* original_path);
 int install_zip_package(const char* zip_path_filename);