diff --git a/include/c11/threads_posix.h b/include/c11/threads_posix.h
index 7bf6a0f6ef6..2d7ac1326de 100644
--- a/include/c11/threads_posix.h
+++ b/include/c11/threads_posix.h
@@ -382,7 +382,7 @@ tss_set(tss_t key, void *val)
 
 /*-------------------- 7.25.7 Time functions --------------------*/
 // 7.25.6.1
-#if 0
+#ifdef __HAIKU__
 static inline int
 timespec_get(struct timespec *ts, int base)
 {