diff --git a/libc/include/sys/mman.h b/libc/include/sys/mman.h
index 6857f60..a19ceb5 100644
--- a/libc/include/sys/mman.h
+++ b/libc/include/sys/mman.h
@@ -59,7 +59,7 @@
 extern int munmap(void*, size_t);
 extern int msync(const void*, size_t, int);
 extern int mprotect(const void*, size_t, int);
-extern void* mremap(void*, size_t, size_t, unsigned long);
+extern void* mremap(void*, size_t, size_t, int, ...);
 
 extern int mlockall(int);
 extern int munlockall(void);