--- a/arch/um/os-Linux/user_syms.c
+++ b/arch/um/os-Linux/user_syms.c
@@ -23,7 +23,7 @@ extern int printf(const char *, ...);
 EXPORT_SYMBOL(strstr);
 #endif
 
-#ifndef __x86_64__
+#if !defined(__x86_64) || (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || (__GNUC__ < 4)
 extern void *memcpy(void *, const void *, size_t);
 EXPORT_SYMBOL(memcpy);
 #endif
