diff --git a/lib/std/c.zig b/lib/std/c.zig
index f4fff3582d64b7732a9cc596aa1aaec45bac89b5..e653d602b5a8dc1fe465483e5a098d21dacd67a1 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -11056,6 +11056,10 @@ pub const pthread_cancelstate = switch (native_os) {
         ENABLE = 1,
         DISABLE = 0,
     },
+    .haiku => enum(c_int) {
+        ENABLE = 0,
+        DISABLE = 1,
+    },
     .linux => if (native_abi.isMusl()) enum(c_int) {
         ENABLE = 0,
         DISABLE = 1,