Index: src/shmif/arcan_shmif_privsep.c
--- src/shmif/arcan_shmif_privsep.c.orig
+++ src/shmif/arcan_shmif_privsep.c
@@ -1,3 +1,7 @@
+#ifdef __OpenBSD__
+#include <pthread.h>
+#endif
+
 #include <arcan_shmif.h>
 
 #ifdef __OpenBSD__
