diff --git a/grep.c b/grep.c
index c7e1dc1e0e..a54e5d86a9 100644
--- a/grep.c
+++ b/grep.c
@@ -1267,6 +1267,7 @@ static void show_line(struct grep_opt *opt,
 		regmatch_t match;
 		enum grep_context ctx = GREP_CONTEXT_BODY;
 		int eflags = 0;
+		const char *start = bol;
 
 		if (want_color(opt->color)) {
 			if (sign == ':')
@@ -1285,6 +1286,7 @@ static void show_line(struct grep_opt *opt,
 			if (match.rm_so == match.rm_eo)
 				break;
 
+			cno = bol - start + match.rm_so + 1;
 			if (opt->only_matching)
 				show_line_header(opt, name, lno, cno, sign);
 			else
@@ -1294,7 +1296,6 @@ static void show_line(struct grep_opt *opt,
 			if (opt->only_matching)
 				opt->output(opt, "\n", 1);
 			bol += match.rm_eo;
-			cno += match.rm_eo;
 			rest -= match.rm_eo;
 			eflags = REG_NOTBOL;
 		}
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index 64ac4f04ee..bd439563d6 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -322,11 +322,11 @@ do
 		${HC}file:1:5:mmap
 		${HC}file:2:5:mmap
 		${HC}file:3:5:mmap
-		${HC}file:3:13:mmap
+		${HC}file:3:14:mmap
 		${HC}file:4:5:mmap
-		${HC}file:4:13:mmap
+		${HC}file:4:14:mmap
 		${HC}file:5:5:mmap
-		${HC}file:5:13:mmap
+		${HC}file:5:14:mmap
 		EOF
 		git grep --column -n -o -e mmap $H >actual &&
 		test_cmp expected actual