diff --git a/usr.bin/diff3/diff3.1 b/usr.bin/diff3/diff3.1
--- a/usr.bin/diff3/diff3.1
+++ b/usr.bin/diff3/diff3.1
@@ -40,6 +40,7 @@
 .Nm diff3
 .Op Fl 3aEeiXx
 .Op Fl Fl diff-program Ar program
+.Op Fl Fl strip-trailing-cr
 .Op Fl L | Fl Fl label Ar label1
 .Op Fl L | Fl Fl label Ar label2
 .Op Fl L | Fl Fl label Ar label3
@@ -125,6 +126,8 @@
 instead of the default
 .Xr diff 1
 to compare files.
+.It Fl Fl strip-trailing-cr
+Strip trailing carriage return on input files.
 .El
 .Pp
 The
diff --git a/usr.bin/diff3/diff3.c b/usr.bin/diff3/diff3.c
--- a/usr.bin/diff3/diff3.c
+++ b/usr.bin/diff3/diff3.c
@@ -264,6 +264,12 @@
 	if ((len = getline(&buf, &bufsize, b)) < 0)
 		return (NULL);
 
+	if (strip_cr && len >= 2 && strcmp("\r\n", &(buf[len - 2])) == 0) {
+		buf[len - 2] = '\n';
+		buf[len - 1] = '\0';
+		len--;
+	}
+
 	if (n != NULL)
 		*n = len;
 
@@ -599,7 +605,7 @@
 	char *labels[] = { NULL, NULL, NULL };
 	const char *diffprog = DIFF_PATH;
 	char *file1, *file2, *file3;
-	char *diffargv[6];
+	char *diffargv[7];
 	int diffargc = 0;
 	int fd13[2], fd23[2];
 	int pd13, pd23;
@@ -657,6 +663,7 @@
 			break;
 		case STRIPCR_OPT:
 			strip_cr = 1;
+			diffargv[diffargc++] = __DECONST(char *, "--strip-trailing-cr");
 			break;
 		}
 	}
diff --git a/usr.bin/diff3/tests/1cr.txt b/usr.bin/diff3/tests/1cr.txt
new file mode 100644
--- /dev/null
+++ b/usr.bin/diff3/tests/1cr.txt
@@ -0,0 +1,6 @@
+This is a more complete test
+which multiple lines
+and a few typ0s to fix
+also I plan to add few lines
+    and to remove
+other lines
diff --git a/usr.bin/diff3/tests/Makefile b/usr.bin/diff3/tests/Makefile
--- a/usr.bin/diff3/tests/Makefile
+++ b/usr.bin/diff3/tests/Makefile
@@ -6,6 +6,7 @@
 
 ${PACKAGE}FILES+=	\
 	1.txt \
+	1cr.txt \
 	2.txt \
 	3.txt \
 	1.out \
diff --git a/usr.bin/diff3/tests/diff3_test.sh b/usr.bin/diff3/tests/diff3_test.sh
--- a/usr.bin/diff3/tests/diff3_test.sh
+++ b/usr.bin/diff3/tests/diff3_test.sh
@@ -8,6 +8,9 @@
 	atf_check -o file:$(atf_get_srcdir)/1.out \
 		diff3 $(atf_get_srcdir)/1.txt $(atf_get_srcdir)/2.txt $(atf_get_srcdir)/3.txt
 
+	atf_check -o file:$(atf_get_srcdir)/1.out \
+		diff3 --strip-trailing-cr $(atf_get_srcdir)/1cr.txt $(atf_get_srcdir)/2.txt $(atf_get_srcdir)/3.txt
+
 	atf_check -o file:$(atf_get_srcdir)/2.out \
 		diff3 -e $(atf_get_srcdir)/1.txt $(atf_get_srcdir)/2.txt $(atf_get_srcdir)/3.txt