Index: lib/std/typedthreads.nim
--- lib/std/typedthreads.nim.orig
+++ lib/std/typedthreads.nim
@@ -292,7 +292,7 @@ else:
     ##
     ## In other words sets a thread's `affinity`:idx:.
     ## If you don't know what this means, you shouldn't use this proc.
-    when not defined(macosx):
+    when not (defined(macosx) or defined(openbsd)):
       var s {.noinit.}: CpuSet
       cpusetZero(s)
       cpusetIncl(cpu.cint, s)
