1 files changed, 21 insertions, 1 deletions
diff --git a/perl.h b/perl.h
index fc9606438a..8645c393fb 100644
--- a/perl.h
+++ b/perl.h
@@ -2090,6 +2090,26 @@ enum {
 	UNLOCK_SV_MUTEX;				\
     } while (0)
 
+#ifdef HAS_SEM
+#   include <sys/ipc.h>
+#   include <sys/sem.h>
+#   ifndef HAS_UNION_SEMUN	/* Provide the union semun. */
+    union semun {
+	int val;
+	struct semid_ds *buf;
+	unsigned short *array;
+    };
+#   endif
+#   ifdef USE_SEMCTL_SEMUN
+#       define Semctl(id, num, cmd, semun) semctl(id, num, cmd, semun)
+#   else
+#       ifdef USE_SEMCTL_SEMID_DS
+#           define Semctl(id, num, cmd, semun) semctl(id, num, cmd, semun.buf)
+#       endif
+#   endif
+#   ifndef Semctl	/* Place our bets on the semun horse. */
+#       define Semctl(id, num, cmd, semun) semctl(id, num, cmd, semun)
+#   endif
+#endif
 
 #endif /* Include guard */
-