diff --git a/include/lighttpd/utils.h b/include/lighttpd/utils.h
index 2fe24fa..42aff1a 100644
--- a/include/lighttpd/utils.h
+++ b/include/lighttpd/utils.h
@@ -66,7 +66,7 @@ LI_API GString *l_g_string_assign_len(GString *string, const gchar *val, gssize
 LI_API gboolean l_g_string_prefix(GString *str, const gchar *s, gsize len);
 LI_API gboolean l_g_string_suffix(GString *str, const gchar *s, gsize len);
 
-LI_API GString *l_g_string_from_int(GString *dest, gint64 val);
+LI_API void l_g_string_append_int(GString *dest, gint64 val);
 
 LI_API gsize dirent_buf_size(DIR * dirp);
 
diff --git a/src/utils.c b/src/utils.c
index 18a97cc..9ceec91 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -580,19 +580,14 @@ GString *l_g_string_assign_len(GString *string, const gchar *val, gssize len) {
 	return string;
 }
 
-GString *l_g_string_from_int(GString *dest, gint64 v) {
+void l_g_string_append_int(GString *dest, gint64 v) {
 	gchar *buf, *end, swap;
 	guint len;
 	guint64 val;
 
-	if (!dest) {
-		dest = g_string_sized_new(21);
-	} else {
-		g_string_set_size(dest, 21);
-	}
-
-	len = 1;
-	buf = dest->str;
+	buf = dest->str + dest->len;
+	len = dest->len + 1;
+	g_string_set_size(dest, dest->len + 21);
 
 	if (v < 0) {
 		len++;
@@ -622,7 +617,6 @@ GString *l_g_string_from_int(GString *dest, gint64 v) {
 	}
 
 	dest->len = len;
-	return dest;
 }
 
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