Index: ykcs11/utils.c
--- ykcs11/utils.c.orig
+++ ykcs11/utils.c
@@ -88,11 +88,16 @@ CK_RV native_create_mutex(void **mutex) {
     free(mtx);
     return CKR_CANT_LOCK;
   }
+#ifndef __OpenBSD__
+  /* no process-shared mutexes on OoenBSD; this was added in a "Enable
+   * forked processes to use the library" commit which doesn't seem to
+   * be needed for yubico-piv-tool */
   if(pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED)) {
     pthread_mutexattr_destroy(&mattr);
     free(mtx);
     return CKR_CANT_LOCK;
   }
+#endif
   if(pthread_mutex_init(mtx, &mattr)) {
     pthread_mutexattr_destroy(&mattr);
     free(mtx);
