diff --git a/src/utils.ts b/src/utils.ts
index 868cdbe..41bec29 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -16,7 +16,7 @@ export function parseAndTransformHtmlByTag(
   const transformContent = (input: string): string => {
     return input.replace(regex, (_match, tagName, content) => {
       const transformFn = transformMap[tagName]
-      let transformedContent = transformFn ? transformFn(content) : content
+      const transformedContent = transformFn ? transformFn(content) : content
       return transformedContent
     })
   }
@@ -66,10 +66,10 @@ export function parseYamlBoolean(value: string): boolean | null {
   return null
 }
 
-function increment(value: number) {
+function increment(value: number): number {
   return value + 1
 }
 
-function decrement(value: number) {
+function decrement(value: number): number {
   return value - 1
 }