diff --git a/merge-recursive.c b/merge-recursive.c
index b5c3c5314f8a4b30dc19b12f311383dd189ae3db..fad7b2c2b8f186fb0129dd1167677c5c2f42b326 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -171,7 +171,7 @@ static void output(struct merge_options *o, int v, const char *fmt, ...)
 	strbuf_vaddf(&o->obuf, fmt, ap);
 	va_end(ap);
 
-	strbuf_add(&o->obuf, "\n", 1);
+	strbuf_addch(&o->obuf, '\n');
 	if (!o->buffer_output)
 		flush_output(o);
 }
diff --git a/pathspec.c b/pathspec.c
index 80430999553d8fda8d095b007bb08c1999bf6993..89f2c8ffff703b98f360590bfcecf165a6df4aef 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -338,7 +338,7 @@ static void NORETURN unsupported_magic(const char *pattern,
 		if (!(magic & m->bit))
 			continue;
 		if (sb.len)
-			strbuf_addstr(&sb, " ");
+			strbuf_addch(&sb, ' ');
 		if (short_magic & m->bit)
 			strbuf_addf(&sb, "'%c'", m->mnemonic);
 		else
diff --git a/url.c b/url.c
index 335d97d3f74e5b7d7139e223fbe1d19837a72e81..7ca2a69e1091fc57cb292052015c920499fe3379 100644
--- a/url.c
+++ b/url.c
@@ -121,7 +121,7 @@ void end_url_with_slash(struct strbuf *buf, const char *url)
 {
 	strbuf_addstr(buf, url);
 	if (buf->len && buf->buf[buf->len - 1] != '/')
-		strbuf_addstr(buf, "/");
+		strbuf_addch(buf, '/');
 }
 
 void str_end_url_with_slash(const char *url, char **dest) {