diff --git a/man/man1/notmuch-dump.1 b/man/man1/notmuch-dump.1
index 64abf014..5d1e1972 100644
--- a/man/man1/notmuch-dump.1
+++ b/man/man1/notmuch-dump.1
@@ -5,15 +5,14 @@ notmuch-dump \- creates a plain-text dump of the tags of each message
 .SH SYNOPSIS
 
 .B "notmuch dump"
-.RI "[ <" filename "> ] [--]"
+.RI "[ --output=<" filename "> ] [--]"
 .RI "[ <" search-term ">...]"
 
 .SH DESCRIPTION
 
 Dump tags for messages matching the given search terms.
 
-Output is to the given filename, if any, or to stdout.  Note that
-using the filename argument is deprecated.
+Output is to the given filename, if any, or to stdout.
 
 These tags are the only data in the notmuch database that can't be
 recreated from the messages themselves.  The output of notmuch dump is
diff --git a/notmuch-dump.c b/notmuch-dump.c
index 37432142..d8186fbc 100644
--- a/notmuch-dump.c
+++ b/notmuch-dump.c
@@ -44,7 +44,7 @@ notmuch_dump_command (unused (void *ctx), int argc, char *argv[])
     int opt_index;
 
     notmuch_opt_desc_t options[] = {
-	{ NOTMUCH_OPT_POSITION, &output_file_name, 0, 0, 0  },
+	{ NOTMUCH_OPT_STRING, &output_file_name, "output", 'o', 0  },
 	{ 0, 0, 0, 0, 0 }
     };
 
@@ -56,7 +56,6 @@ notmuch_dump_command (unused (void *ctx), int argc, char *argv[])
     }
 
     if (output_file_name) {
-	fprintf (stderr, "Warning: the output file argument of dump is deprecated.\n");
 	output = fopen (output_file_name, "w");
 	if (output == NULL) {
 	    fprintf (stderr, "Error opening %s for writing: %s\n",
diff --git a/test/dump-restore b/test/dump-restore
index 439e9980..c7801cfc 100755
--- a/test/dump-restore
+++ b/test/dump-restore
@@ -53,16 +53,12 @@ test_expect_success 'Restore with nothing to do, III' \
 test_expect_success 'Invalid restore invocation' \
   'test_must_fail notmuch restore dump.expected another_one'
 
-test_begin_subtest "dump outfile"
-notmuch dump dump-outfile.actual
+test_begin_subtest "dump --output=outfile"
+notmuch dump --output=dump-outfile.actual
 test_expect_equal_file dump.expected dump-outfile.actual
 
-test_begin_subtest "dump outfile # deprecated"
-test_expect_equal "Warning: the output file argument of dump is deprecated."\
-  "$(notmuch dump /dev/null 2>&1)"
-
-test_begin_subtest "dump outfile --"
-notmuch dump dump-1-arg-dash.actual --
+test_begin_subtest "dump --output=outfile --"
+notmuch dump --output=dump-1-arg-dash.actual --
 test_expect_equal_file dump.expected dump-1-arg-dash.actual
 
 # Note, we assume all messages from cworth have a message-id
@@ -74,12 +70,12 @@ test_begin_subtest "dump -- from:cworth"
 notmuch dump -- from:cworth > dump-dash-cworth.actual
 test_expect_equal_file dump-cworth.expected dump-dash-cworth.actual
 
-test_begin_subtest "dump outfile from:cworth"
-notmuch dump dump-outfile-cworth.actual from:cworth
+test_begin_subtest "dump --output=outfile from:cworth"
+notmuch dump --output=dump-outfile-cworth.actual from:cworth
 test_expect_equal_file dump-cworth.expected dump-outfile-cworth.actual
 
-test_begin_subtest "dump outfile -- from:cworth"
-notmuch dump dump-outfile-dash-inbox.actual -- from:cworth
+test_begin_subtest "dump --output=outfile -- from:cworth"
+notmuch dump --output=dump-outfile-dash-inbox.actual -- from:cworth
 test_expect_equal_file dump-cworth.expected dump-outfile-dash-inbox.actual
 
 test_done
diff --git a/test/maildir-sync b/test/maildir-sync
index cd7d2418..0914fa52 100755
--- a/test/maildir-sync
+++ b/test/maildir-sync
@@ -124,7 +124,7 @@ mv $MAIL_DIR/cur/adding-replied-tag:2,RS $MAIL_DIR/cur/adding-replied-tag:2,S
 mv $MAIL_DIR/cur/adding-s-flag:2,S $MAIL_DIR/cur/adding-s-flag:2,
 mv $MAIL_DIR/cur/adding-with-s-flag:2,S $MAIL_DIR/cur/adding-with-s-flag:2,RS
 mv $MAIL_DIR/cur/message-to-move-to-cur:2,S $MAIL_DIR/cur/message-to-move-to-cur:2,DS
-notmuch dump dump.txt
+notmuch dump --output=dump.txt
 NOTMUCH_NEW >/dev/null
 notmuch restore dump.txt
 output=$(ls $MAIL_DIR/cur)