diff --git a/builtin/notes.c b/builtin/notes.c
index ae981085ea..cb011303e6 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -179,7 +179,7 @@ static void write_commented_object(int fd, const struct object_id *object)
 
 	if (strbuf_read(&buf, show.out, 0) < 0)
 		die_errno(_("could not read 'show' output"));
-	strbuf_add_commented_lines(&cbuf, buf.buf, buf.len, comment_line_char);
+	strbuf_add_commented_lines(&cbuf, buf.buf, buf.len, comment_line_str);
 	write_or_die(fd, cbuf.buf, cbuf.len);
 
 	strbuf_release(&cbuf);
@@ -207,10 +207,10 @@ static void prepare_note_data(const struct object_id *object, struct note_data *
 			copy_obj_to_fd(fd, old_note);
 
 		strbuf_addch(&buf, '\n');
-		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_char);
+		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_str);
 		strbuf_add_commented_lines(&buf, _(note_template), strlen(_(note_template)),
-					   comment_line_char);
-		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_char);
+					   comment_line_str);
+		strbuf_add_commented_lines(&buf, "\n", strlen("\n"), comment_line_str);
 		write_or_die(fd, buf.buf, buf.len);
 
 		write_commented_object(fd, object);
diff --git a/builtin/stripspace.c b/builtin/stripspace.c
index 434ac490cb..e5626e5126 100644
--- a/builtin/stripspace.c
+++ b/builtin/stripspace.c
@@ -13,7 +13,7 @@ static void comment_lines(struct strbuf *buf)
 	size_t len;
 
 	msg = strbuf_detach(buf, &len);
-	strbuf_add_commented_lines(buf, msg, len, comment_line_char);
+	strbuf_add_commented_lines(buf, msg, len, comment_line_str);
 	free(msg);
 }
 
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
index 66e47449a0..79e8aad086 100644
--- a/fmt-merge-msg.c
+++ b/fmt-merge-msg.c
@@ -510,7 +510,7 @@ static void fmt_tag_signature(struct strbuf *tagbuf,
 	if (sig->len) {
 		strbuf_addch(tagbuf, '\n');
 		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len,
-					   comment_line_char);
+					   comment_line_str);
 	}
 }
 
@@ -557,7 +557,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 				strbuf_add_commented_lines(&tagline,
 						origins.items[first_tag].string,
 						strlen(origins.items[first_tag].string),
-						comment_line_char);
+						comment_line_str);
 				strbuf_insert(&tagbuf, 0, tagline.buf,
 					      tagline.len);
 				strbuf_release(&tagline);
@@ -566,7 +566,7 @@ static void fmt_merge_msg_sigs(struct strbuf *out)
 			strbuf_add_commented_lines(&tagbuf,
 					origins.items[i].string,
 					strlen(origins.items[i].string),
-					comment_line_char);
+					comment_line_str);
 			fmt_tag_signature(&tagbuf, &sig, buf, len);
 		}
 		strbuf_release(&payload);
diff --git a/rebase-interactive.c b/rebase-interactive.c
index affc93a8e4..c343e16fcd 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -78,7 +78,7 @@ void append_todo_help(int command_count,
 				      shortrevisions, shortonto, command_count);
 	}
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_str);
 
 	if (get_missing_commit_check_level() == MISSING_COMMIT_CHECK_ERROR)
 		msg = _("\nDo not remove any line. Use 'drop' "
@@ -87,7 +87,7 @@ void append_todo_help(int command_count,
 		msg = _("\nIf you remove a line here "
 			 "THAT COMMIT WILL BE LOST.\n");
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_str);
 
 	if (edit_todo)
 		msg = _("\nYou are editing the todo file "
@@ -98,7 +98,7 @@ void append_todo_help(int command_count,
 		msg = _("\nHowever, if you remove everything, "
 			"the rebase will be aborted.\n\n");
 
-	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_char);
+	strbuf_add_commented_lines(buf, msg, strlen(msg), comment_line_str);
 }
 
 int edit_todo_list(struct repository *r, struct todo_list *todo_list,
diff --git a/sequencer.c b/sequencer.c
index 051929c9f1..d12c5a8a03 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1853,7 +1853,7 @@ static void add_commented_lines(struct strbuf *buf, const void *str, size_t len)
 		s += count;
 		len -= count;
 	}
-	strbuf_add_commented_lines(buf, s, len, comment_line_char);
+	strbuf_add_commented_lines(buf, s, len, comment_line_str);
 }
 
 /* Does the current fixup chain contain a squash command? */
@@ -1952,7 +1952,7 @@ static int append_squash_message(struct strbuf *buf, const char *body,
 	strbuf_addf(buf, _(nth_commit_msg_fmt),
 		    ++opts->current_fixup_count + 1);
 	strbuf_addstr(buf, "\n\n");
-	strbuf_add_commented_lines(buf, body, commented_len, comment_line_char);
+	strbuf_add_commented_lines(buf, body, commented_len, comment_line_str);
 	/* buf->buf may be reallocated so store an offset into the buffer */
 	fixup_off = buf->len;
 	strbuf_addstr(buf, body + commented_len);
@@ -2043,7 +2043,7 @@ static int update_squash_messages(struct repository *r,
 		strbuf_addstr(&buf, "\n\n");
 		if (is_fixup_flag(command, flag))
 			strbuf_add_commented_lines(&buf, body, strlen(body),
-						   comment_line_char);
+						   comment_line_str);
 		else
 			strbuf_addstr(&buf, body);
 
@@ -2063,7 +2063,7 @@ static int update_squash_messages(struct repository *r,
 			    ++opts->current_fixup_count + 1);
 		strbuf_addstr(&buf, "\n\n");
 		strbuf_add_commented_lines(&buf, body, strlen(body),
-					   comment_line_char);
+					   comment_line_str);
 	} else
 		return error(_("unknown command: %d"), command);
 	repo_unuse_commit_buffer(r, commit, message);
diff --git a/strbuf.c b/strbuf.c
index 76d02e0920..7c8f582127 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -359,13 +359,9 @@ static void add_lines(struct strbuf *out,
 }
 
 void strbuf_add_commented_lines(struct strbuf *out, const char *buf,
-				size_t size, char comment_prefix)
+				size_t size, const char *comment_prefix)
 {
-	char prefix[2];
-
-	prefix[0] = comment_prefix;
-	prefix[1] = '\0';
-	add_lines(out, prefix, buf, size, 1);
+	add_lines(out, comment_prefix, buf, size, 1);
 }
 
 void strbuf_commented_addf(struct strbuf *sb, const char *comment_prefix,
@@ -379,13 +375,7 @@ void strbuf_commented_addf(struct strbuf *sb, const char *comment_prefix,
 	strbuf_vaddf(&buf, fmt, params);
 	va_end(params);
 
-	/*
-	 * TODO Our commented_lines helper does not yet understand
-	 * comment strings. But since we know that the strings are
-	 * always single-char, we can cheat for the moment, and
-	 * fix this later.
-	 */
-	strbuf_add_commented_lines(sb, buf.buf, buf.len, comment_prefix[0]);
+	strbuf_add_commented_lines(sb, buf.buf, buf.len, comment_prefix);
 	if (incomplete_line)
 		sb->buf[--sb->len] = '\0';
 
diff --git a/strbuf.h b/strbuf.h
index b128ca539a..58dddf2777 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -288,7 +288,7 @@ void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
  */
 void strbuf_add_commented_lines(struct strbuf *out,
 				const char *buf, size_t size,
-				char comment_prefix);
+				const char *comment_prefix);
 
 
 /**
diff --git a/wt-status.c b/wt-status.c
index 3845e1d383..ae623e760e 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1028,7 +1028,7 @@ static void wt_longstatus_print_submodule_summary(struct wt_status *s, int uncom
 	if (s->display_comment_prefix) {
 		size_t len;
 		summary_content = strbuf_detach(&summary, &len);
-		strbuf_add_commented_lines(&summary, summary_content, len, comment_line_char);
+		strbuf_add_commented_lines(&summary, summary_content, len, comment_line_str);
 		free(summary_content);
 	}
 
@@ -1104,7 +1104,7 @@ void wt_status_append_cut_line(struct strbuf *buf)
 	const char *explanation = _("Do not modify or remove the line above.\nEverything below it will be ignored.");
 
 	strbuf_commented_addf(buf, comment_line_str, "%s", cut_line);
-	strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_char);
+	strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_str);
 }
 
 void wt_status_add_cut_line(struct wt_status *s)
