diff --git a/builtin/am.c b/builtin/am.c
index d1990d7edc..5bc72d7822 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1286,7 +1286,7 @@ static int parse_mail(struct am_state *state, const char *mail)
 
 	strbuf_addstr(&msg, "\n\n");
 	strbuf_addbuf(&msg, &mi.log_message);
-	strbuf_stripspace(&msg, '\0');
+	strbuf_stripspace(&msg, NULL);
 
 	assert(!state->author_name);
 	state->author_name = strbuf_detach(&author_name, NULL);
diff --git a/builtin/branch.c b/builtin/branch.c
index cfb63cce5f..c03c0407d1 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -678,7 +678,7 @@ static int edit_branch_description(const char *branch_name)
 		strbuf_release(&buf);
 		return -1;
 	}
-	strbuf_stripspace(&buf, comment_line_char);
+	strbuf_stripspace(&buf, comment_line_str);
 
 	strbuf_addf(&name, "branch.%s.description", branch_name);
 	if (buf.len || exists)
diff --git a/builtin/commit.c b/builtin/commit.c
index d8abbe48b1..583bf04be5 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -890,7 +890,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	s->hints = 0;
 
 	if (clean_message_contents)
-		strbuf_stripspace(&sb, '\0');
+		strbuf_stripspace(&sb, NULL);
 
 	if (signoff)
 		append_signoff(&sb, ignored_log_message_bytes(sb.buf, sb.len), 0);
diff --git a/builtin/notes.c b/builtin/notes.c
index caf20fd5bd..ae981085ea 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -223,7 +223,7 @@ static void prepare_note_data(const struct object_id *object, struct note_data *
 			die(_("please supply the note contents using either -m or -F option"));
 		}
 		if (d->stripspace)
-			strbuf_stripspace(&d->buf, comment_line_char);
+			strbuf_stripspace(&d->buf, comment_line_str);
 	}
 }
 
@@ -264,7 +264,7 @@ static void concat_messages(struct note_data *d)
 		if ((d->stripspace == UNSPECIFIED &&
 		     d->messages[i]->stripspace == STRIPSPACE) ||
 		    d->stripspace == STRIPSPACE)
-			strbuf_stripspace(&d->buf, 0);
+			strbuf_stripspace(&d->buf, NULL);
 		strbuf_reset(&msg);
 	}
 	strbuf_release(&msg);
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 6ead9465a4..bf78402129 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -204,7 +204,7 @@ static int edit_todo_file(unsigned flags)
 	if (strbuf_read_file(&todo_list.buf, todo_file, 0) < 0)
 		return error_errno(_("could not read '%s'."), todo_file);
 
-	strbuf_stripspace(&todo_list.buf, comment_line_char);
+	strbuf_stripspace(&todo_list.buf, comment_line_str);
 	res = edit_todo_list(the_repository, &todo_list, &new_todo, NULL, NULL, flags);
 	if (!res && todo_list_write_to_file(the_repository, &new_todo, todo_file,
 					    NULL, NULL, -1, flags & ~(TODO_LIST_SHORTEN_IDS)))
diff --git a/builtin/stripspace.c b/builtin/stripspace.c
index 7b700a9fb1..434ac490cb 100644
--- a/builtin/stripspace.c
+++ b/builtin/stripspace.c
@@ -59,7 +59,7 @@ int cmd_stripspace(int argc, const char **argv, const char *prefix)
 
 	if (mode == STRIP_DEFAULT || mode == STRIP_COMMENTS)
 		strbuf_stripspace(&buf,
-			  mode == STRIP_COMMENTS ? comment_line_char : '\0');
+			  mode == STRIP_COMMENTS ? comment_line_str : NULL);
 	else
 		comment_lines(&buf);
 
diff --git a/builtin/tag.c b/builtin/tag.c
index 19a7e06bf4..07327d3c04 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -310,7 +310,7 @@ static void create_tag(const struct object_id *object, const char *object_ref,
 
 	if (opt->cleanup_mode != CLEANUP_NONE)
 		strbuf_stripspace(buf,
-		  opt->cleanup_mode == CLEANUP_ALL ? comment_line_char : '\0');
+		  opt->cleanup_mode == CLEANUP_ALL ? comment_line_str : NULL);
 
 	if (!opt->message_given && !buf->len)
 		die(_("no tag message?"));
diff --git a/builtin/worktree.c b/builtin/worktree.c
index 9c76b62b02..f0aa962cf8 100644
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -657,7 +657,7 @@ static int can_use_local_refs(const struct add_opts *opts)
 			strbuf_add_real_path(&path, get_worktree_git_dir(NULL));
 			strbuf_addstr(&path, "/HEAD");
 			strbuf_read_file(&contents, path.buf, 64);
-			strbuf_stripspace(&contents, 0);
+			strbuf_stripspace(&contents, NULL);
 			strbuf_strip_suffix(&contents, "\n");
 
 			warning(_("HEAD points to an invalid (or orphaned) reference.\n"
diff --git a/gpg-interface.c b/gpg-interface.c
index 95e764acb1..b5993385ff 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -586,8 +586,8 @@ static int verify_ssh_signed_buffer(struct signature_check *sigc,
 		}
 	}
 
-	strbuf_stripspace(&ssh_keygen_out, '\0');
-	strbuf_stripspace(&ssh_keygen_err, '\0');
+	strbuf_stripspace(&ssh_keygen_out, NULL);
+	strbuf_stripspace(&ssh_keygen_err, NULL);
 	/* Add stderr outputs to show the user actual ssh-keygen errors */
 	strbuf_add(&ssh_keygen_out, ssh_principals_err.buf, ssh_principals_err.len);
 	strbuf_add(&ssh_keygen_out, ssh_keygen_err.buf, ssh_keygen_err.len);
diff --git a/rebase-interactive.c b/rebase-interactive.c
index d9718409b3..6dfc33e4e3 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -130,7 +130,7 @@ int edit_todo_list(struct repository *r, struct todo_list *todo_list,
 	if (launch_sequence_editor(todo_file, &new_todo->buf, NULL))
 		return -2;
 
-	strbuf_stripspace(&new_todo->buf, comment_line_char);
+	strbuf_stripspace(&new_todo->buf, comment_line_str);
 	if (initial && new_todo->buf.len == 0)
 		return -3;
 
diff --git a/sequencer.c b/sequencer.c
index f49a871ac0..6a1b7b200e 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1152,7 +1152,7 @@ void cleanup_message(struct strbuf *msgbuf,
 		strbuf_setlen(msgbuf, wt_status_locate_end(msgbuf->buf, msgbuf->len));
 	if (cleanup_mode != COMMIT_MSG_CLEANUP_NONE)
 		strbuf_stripspace(msgbuf,
-		  cleanup_mode == COMMIT_MSG_CLEANUP_ALL ? comment_line_char : '\0');
+		  cleanup_mode == COMMIT_MSG_CLEANUP_ALL ? comment_line_str : NULL);
 }
 
 /*
@@ -1184,7 +1184,7 @@ int template_untouched(const struct strbuf *sb, const char *template_file,
 		return 0;
 
 	strbuf_stripspace(&tmpl,
-	  cleanup_mode == COMMIT_MSG_CLEANUP_ALL ? comment_line_char : '\0');
+	  cleanup_mode == COMMIT_MSG_CLEANUP_ALL ? comment_line_str : NULL);
 	if (!skip_prefix(sb->buf, tmpl.buf, &start))
 		start = sb->buf;
 	strbuf_release(&tmpl);
@@ -1557,7 +1557,7 @@ static int try_to_commit(struct repository *r,
 
 	if (cleanup != COMMIT_MSG_CLEANUP_NONE)
 		strbuf_stripspace(msg,
-		  cleanup == COMMIT_MSG_CLEANUP_ALL ? comment_line_char : '\0');
+		  cleanup == COMMIT_MSG_CLEANUP_ALL ? comment_line_str : NULL);
 	if ((flags & EDIT_MSG) && message_is_empty(msg, cleanup)) {
 		res = 1; /* run 'git commit' to display error message */
 		goto out;
diff --git a/strbuf.c b/strbuf.c
index a33aed6c07..e9b6127e76 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -1001,10 +1001,10 @@ static size_t cleanup(char *line, size_t len)
  *
  * If last line does not have a newline at the end, one is added.
  *
- * Pass a non-NUL comment_prefix to skip every line starting
+ * Pass a non-NULL comment_prefix to skip every line starting
  * with it.
  */
-void strbuf_stripspace(struct strbuf *sb, char comment_prefix)
+void strbuf_stripspace(struct strbuf *sb, const char *comment_prefix)
 {
 	size_t empties = 0;
 	size_t i, j, len, newlen;
@@ -1018,7 +1018,7 @@ void strbuf_stripspace(struct strbuf *sb, char comment_prefix)
 		len = eol ? eol - (sb->buf + i) + 1 : sb->len - i;
 
 		if (comment_prefix && len &&
-		    sb->buf[i] == comment_prefix) {
+		    starts_with(sb->buf + i, comment_prefix)) {
 			newlen = 0;
 			continue;
 		}
diff --git a/strbuf.h b/strbuf.h
index 860fcec5fb..dc4710adbb 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -513,11 +513,11 @@ int strbuf_getcwd(struct strbuf *sb);
 int strbuf_normalize_path(struct strbuf *sb);
 
 /**
- * Strip whitespace from a buffer. If comment_prefix is non-NUL,
+ * Strip whitespace from a buffer. If comment_prefix is non-NULL,
  * then lines beginning with that character are considered comments,
  * thus removed.
  */
-void strbuf_stripspace(struct strbuf *buf, char comment_prefix);
+void strbuf_stripspace(struct strbuf *buf, const char *comment_prefix);
 
 static inline int strbuf_strip_suffix(struct strbuf *sb, const char *suffix)
 {