diff --git a/usr.bin/uniq/tests/uniq_test.sh b/usr.bin/uniq/tests/uniq_test.sh
--- a/usr.bin/uniq/tests/uniq_test.sh
+++ b/usr.bin/uniq/tests/uniq_test.sh
@@ -53,7 +53,12 @@
 count_repeated_body() {
 	printf "a\na\nb\nb\na\n" >input
 	printf "   2 a\n   2 b\n" >expected
+	atf_check_uniq -cd
+	atf_check_uniq -c -d
+	atf_check_uniq -dc
+	atf_check_uniq -d -c
 	atf_check_uniq --count --repeated
+	atf_check_uniq --repeated --count
 }
 
 atf_test_case all_repeated
@@ -64,7 +69,15 @@
 	printf "a\na\nb\na\na\n" >input
 	printf "a\na\na\na\n" >expected
 	atf_check_uniq -D
+	atf_check_uniq -Dnone
 	atf_check_uniq --all-repeated
+	atf_check_uniq --all-repeated=none
+	printf "\na\na\n\na\na\n" >expected
+	atf_check_uniq -Dprepend
+	atf_check_uniq --all-repeated=prepend
+	printf "a\na\n\na\na\n" >expected
+	atf_check_uniq -Dseparate
+	atf_check_uniq --all-repeated=separate
 }
 
 atf_test_case skip_fields
diff --git a/usr.bin/uniq/uniq.1 b/usr.bin/uniq/uniq.1
--- a/usr.bin/uniq/uniq.1
+++ b/usr.bin/uniq/uniq.1
@@ -28,7 +28,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd January 12, 2024
+.Dd December 9, 2024
 .Dt UNIQ 1
 .Os
 .Sh NAME
@@ -36,8 +36,8 @@
 .Nd report or filter out repeated lines in a file
 .Sh SYNOPSIS
 .Nm
-.Op Fl c | Fl d | Fl D | Fl u
-.Op Fl i
+.Op Fl cdiu
+.Op Fl D Ns Op Ar septype
 .Op Fl f Ar num
 .Op Fl s Ar chars
 .Oo
diff --git a/usr.bin/uniq/uniq.c b/usr.bin/uniq/uniq.c
--- a/usr.bin/uniq/uniq.c
+++ b/usr.bin/uniq/uniq.c
@@ -366,7 +366,7 @@
 static void
 usage(void)
 {
-	(void)fprintf(stderr,
-"usage: uniq [-c | -d | -D | -u] [-i] [-f fields] [-s chars] [input [output]]\n");
+	(void)fprintf(stderr, "usage: uniq [-cdiu] [-D[septype]] "
+	    "[-f fields] [-s chars] [input [output]]\n");
 	exit(1);
 }