diff --git a/modules/git/grep.go b/modules/git/grep.go
index 3aa1442d29..8a896bc5aa 100644
--- a/modules/git/grep.go
+++ b/modules/git/grep.go
@@ -85,6 +85,9 @@ func GrepSearch(ctx context.Context, repo *Repository, search string, opts GrepO
 		"-I", "--null", "--break", "--heading",
 		"--line-number", "--ignore-case", "--full-name")
 	if opts.Mode == RegExpGrepMode {
+		// No `--column` -- regexp mode does not support highlighting in the
+		// current implementation as the length of the match is unknown from
+		// `grep` but required for highlighting.
 		cmd.AddArguments("--perl-regexp")
 	} else {
 		cmd.AddArguments("--fixed-strings", "--column")
@@ -161,6 +164,7 @@ func GrepSearch(ctx context.Context, repo *Repository, search string, opts GrepO
 				if lineNum, lineCode, ok := strings.Cut(line, "\x00"); ok {
 					lineNumInt, _ := strconv.Atoi(lineNum)
 					res.LineNumbers = append(res.LineNumbers, lineNumInt)
+					// We support highlighting only when `--column` parameter is used.
 					if lineCol, lineCode2, ok := strings.Cut(lineCode, "\x00"); ok {
 						lineColInt, _ := strconv.Atoi(lineCol)
 						start := lineColInt - 1