diff --git a/include/lib/libc/stdlib.h b/include/lib/libc/stdlib.h
index 4e5a824..cf30ef3 100644
--- a/include/lib/libc/stdlib.h
+++ b/include/lib/libc/stdlib.h
@@ -29,4 +29,6 @@
 unsigned long strtoul(const char *nptr, char **endptr, int base);
 long long strtoll(const char *nptr, char **endptr, int base);
 unsigned long long strtoull(const char *nptr, char **endptr, int base);
+void qsort(void *, size_t, size_t,
+           int (* _Nonnull)(const void *, const void *));
 #endif /* STDLIB_H */