diff --git a/include/linux/string.h b/include/linux/string.h
index 3606620..5d63be4 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -94,6 +94,7 @@
 #ifndef __HAVE_ARCH_STRDUP
 extern char * strdup(const char *);
 #endif
+extern char * strndup(const char *, size_t);
 #ifndef __HAVE_ARCH_STRSWAB
 extern char * strswab(const char *);
 #endif