diff --git a/library/std/src/sys/unix/process/process_unix.rs b/library/std/src/sys/unix/process/process_unix.rs
index ef29aa3c8907888d4aa8c4f26564dc9cd5fc898e..75bb92437fd929e9034b9c5089037f24d98998cd 100644
--- a/library/std/src/sys/unix/process/process_unix.rs
+++ b/library/std/src/sys/unix/process/process_unix.rs
@@ -730,6 +730,7 @@ fn signal_string(signal: i32) -> &'static str {
         libc::SIGVTALRM => " (SIGVTALRM)",
         libc::SIGPROF => " (SIGPROF)",
         libc::SIGWINCH => " (SIGWINCH)",
+        #[cfg(not(target_os = "haiku"))]
         libc::SIGIO => " (SIGIO)",
         libc::SIGSYS => " (SIGSYS)",
         // For information on Linux signals, run `man 7 signal`