diff --git a/src/rules/yaml-key-sort.ts b/src/rules/yaml-key-sort.ts
index f86b95e9..e3536de1 100644
--- a/src/rules/yaml-key-sort.ts
+++ b/src/rules/yaml-key-sort.ts
@@ -63,6 +63,10 @@ export default class YamlKeySort extends RuleBuilder<YamlKeySortOptions> {
     const doc = parseYAML(yamlText);
     const startingPriorityKeys = getEmptyDocument(doc);
 
+    if (doc.contents == null) {
+      return text;
+    }
+
     let remainingKeys = this.getYAMLKeysSorted(yamlKeys, doc, startingPriorityKeys);
 
     const sortOrder = options.yamlSortOrderForOtherKeys;