Index: lib/posix/posix.nim
--- lib/posix/posix.nim.orig
+++ lib/posix/posix.nim
@@ -275,7 +275,7 @@ proc setlocale*(a1: cint, a2: cstring): cstring {.
 proc strfmon*(a1: cstring, a2: int, a3: cstring): int {.varargs,
    importc, header: "<monetary.h>".}
 
-when not (defined(nintendoswitch) or defined(macos) or defined(macosx)):
+when not (defined(nintendoswitch) or defined(macos) or defined(macosx) or defined(openbsd)):
   proc mq_notify*(mqdes: Mqd, event: ptr SigEvent): cint {.
     importc, header: "<mqueue.h>".}
 
