diff --git a/src/cmd/ksh93/sh/args.c b/src/cmd/ksh93/sh/args.c
index 5756ec412..527639d4d 100644
--- a/src/cmd/ksh93/sh/args.c
+++ b/src/cmd/ksh93/sh/args.c
@@ -36,8 +36,10 @@
 #include	"FEATURE/poll"
 #if SHOPT_KIA
 #   include	"shlex.h"
+#endif
+#if SHOPT_KIA || SHOPT_DEVFD
 #   include	"io.h"
-#endif /* SHOPT_KIA */
+#endif
 #if SHOPT_PFSH
 #   define PFSHOPT	"P"
 #else
@@ -701,12 +703,15 @@ struct argnod *sh_argprocsub(Shell_t *shp,struct argnod *argp)
 	sh_pipe(pv);
 #else
 	pv[0] = -1;
-	while((shp->fifo = pathtemp(0,0,0,"ksh.fifo",0), mkfifo(shp->fifo,0))<0)
+	while(shp->fifo = pathtemp(0,0,0,"ksh.fifo",0), shp->fifo && mkfifo(shp->fifo,0)<0)
 	{
 		if(errno==EEXIST || errno==EACCES || errno==ENOENT || errno==ENOTDIR || errno==EROFS)
 			continue;		/* lost race (name conflict or tmp dir change); try again */
-		errormsg(SH_DICT,ERROR_system(128),"process substitution: FIFO creation failed");
+		shp->fifo = 0;
+		break;
 	}
+	if(!shp->fifo)
+		errormsg(SH_DICT,ERROR_system(128),"process substitution: FIFO creation failed");
 	chmod(shp->fifo,S_IRUSR|S_IWUSR);	/* mkfifo + chmod works regardless of umask */
 	sfputr(shp->stk,shp->fifo,0);
 #endif /* SHOPT_DEVFD */