diff --git a/init/version.c b/init/version.c
index 9d17d70..041fd82 100644
--- a/init/version.c
+++ b/init/version.c
@@ -16,6 +16,7 @@
 #define version(a) Version_ ## a
 #define version_string(a) version(a)
 
+extern int version_string(LINUX_VERSION_CODE);
 int version_string(LINUX_VERSION_CODE);
 
 struct uts_namespace init_uts_ns = {