diff --git a/qa/kern/build.json b/qa/kern/build.json
index 8d9b9a3..5072cae 100644
--- a/qa/kern/build.json
+++ b/qa/kern/build.json
@@ -16,6 +16,7 @@
 			"awake_note1.c",
 			"brk.c",
 			"broken.c",
+			"dup.c",
 			"execl.c",
 			"float.c",
 			"fork.c",
diff --git a/qa/kern/dup.c b/qa/kern/dup.c
new file mode 100644
index 0000000..d464c22
--- /dev/null
+++ b/qa/kern/dup.c
@@ -0,0 +1,70 @@
+/*
+ * This file is part of Jehanne.
+ *
+ * Copyright (C) 2015 Giacomo Tesio <giacomo@tesio.it>
+ *
+ * Jehanne is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * Jehanne is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Jehanne.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <u.h>
+#include <lib9.h>
+
+/* check devdup Nctl format */
+
+
+void
+main(void)
+{
+	char buf[256];
+	int fd, r;
+
+	fd = open("/fd/0ctl", OREAD|OCEXEC);
+	if(fd < 0)
+		goto Fail;
+	r = read(fd, buf, sizeof(buf));
+	if(r < 0)
+		goto Fail;
+	close(fd);
+	print("Got 0ctl: %s\n", buf);
+
+	fd = open("/fd/1ctl", OREAD|OCEXEC);
+	if(fd < 0)
+		goto Fail;
+	r = read(fd, buf, sizeof(buf));
+	if(r < 0)
+		goto Fail;
+	close(fd);
+	print("Got 1ctl: %s\n", buf);
+
+	fd = open("/fd/2ctl", OREAD|OCEXEC);
+	if(fd < 0)
+		goto Fail;
+	r = read(fd, buf, sizeof(buf));
+	if(r < 0)
+		goto Fail;
+	print("Got 2ctl: %s\n", buf);
+
+	snprint(buf, sizeof(buf), "/fd/%dctl", fd);
+	fd = open(buf, OREAD);
+	if(fd < 0)
+		goto Fail;
+	r = read(fd, buf, sizeof(buf));
+	if(r < 0)
+		goto Fail;
+	print("Got: %s\n", buf);
+	close(fd);
+	exits(nil);
+
+Fail:
+	print("FAIL\n");
+	exits("FAIL");
+}
diff --git a/qa/kern/dup.runner b/qa/kern/dup.runner
new file mode 100755
index 0000000..369bbab
--- /dev/null
+++ b/qa/kern/dup.runner
@@ -0,0 +1,37 @@
+#!/cmd/rc
+
+runner=$0
+test = `{echo $runner|sed 's/.runner//'}
+test_output = /tmp/output-`{basename $test}
+
+if ( test -e $test_output) rm $test_output
+
+$test > $test_output
+testpid=$apid
+
+wait $testpid
+
+if ( ! cat $test_output | grep 'Got 0ctl:   0  r   ' > /dev/null ) {
+	cat $test_output
+	echo FAIL
+	exit FAIL
+}
+if ( ! cat $test_output | grep 'Got 1ctl:   1  w   ' > /dev/null ) {
+	cat $test_output
+	echo FAIL
+	exit FAIL
+}
+if ( ! cat $test_output | grep 'Got 2ctl:   2  w   ' > /dev/null ) {
+	cat $test_output
+	echo FAIL
+	exit FAIL
+}
+if ( ! cat $test_output | grep 'Got:   3  rE  ' > /dev/null ) {
+	cat $test_output
+	echo FAIL
+	exit FAIL
+}
+
+rm $test_output
+echo PASS
+exit PASS
diff --git a/sys/src/kern/port/devproc.c b/sys/src/kern/port/devproc.c
index bf019cf..5588c04 100644
--- a/sys/src/kern/port/devproc.c
+++ b/sys/src/kern/port/devproc.c
@@ -564,11 +564,11 @@ _procfdprint(Chan *c, int fd, int w, char *s, int ns, char *modestr)
 {
 	int n;
 	char *flags;
-	if((c->mode&(OCEXEC|ORCLOSE)) == (OCEXEC|ORCLOSE))
+	if((c->flag&(OCEXEC|ORCLOSE)) == (OCEXEC|ORCLOSE))
 		flags = "ED";
-	else if(c->mode&OCEXEC)
+	else if(c->flag&OCEXEC)
 		flags = "E ";
-	else if(c->mode&ORCLOSE)
+	else if(c->flag&ORCLOSE)
 		flags = "D ";
 	else
 		flags = "  ";