diff --git a/src/os_unix.c b/src/os_unix.c
index 043d0a8..860fbcc 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3734,24 +3734,21 @@
 
     while (wait_pid != child)
     {
-# ifdef _THREAD_SAFE
-	/* Ugly hack: when compiled with Python threads are probably
-	 * used, in which case wait() sometimes hangs for no obvious
-	 * reason.  Use waitpid() instead and loop (like the GUI). */
-#  ifdef __NeXT__
+	/* When compiled with Python threads are probably used, in which case
+	 * wait() sometimes hangs for no obvious reason.  Use waitpid()
+	 * instead and loop (like the GUI). Also needed for other interfaces,
+	 * they might call system(). */
+# ifdef __NeXT__
 	wait_pid = wait4(child, status, WNOHANG, (struct rusage *)0);
-#  else
+# else
 	wait_pid = waitpid(child, status, WNOHANG);
-#  endif
+# endif
 	if (wait_pid == 0)
 	{
 	    /* Wait for 1/100 sec before trying again. */
 	    mch_delay(10L, TRUE);
 	    continue;
 	}
-# else
-	wait_pid = wait(status);
-# endif
 	if (wait_pid <= 0
 # ifdef ECHILD
 		&& errno == ECHILD