diff --git a/src/boot/efi/util.h b/src/boot/efi/util.h
index 8518dfde77..b13f22476c 100644
--- a/src/boot/efi/util.h
+++ b/src/boot/efi/util.h
@@ -55,7 +55,7 @@ static inline void FileHandleClosep(EFI_FILE_HANDLE *handle) {
         uefi_call_wrapper((*handle)->Close, 1, *handle);
 }
 
-const EFI_GUID loader_guid;
+extern const EFI_GUID loader_guid;
 
 #define UINTN_MAX (~(UINTN)0)
 #define INTN_MAX ((INTN)(UINTN_MAX>>1))