diff --git a/src/config/config.ts b/src/config/config.ts
index ad55b176b..3e51b06b0 100644
--- a/src/config/config.ts
+++ b/src/config/config.ts
@@ -712,7 +712,7 @@ const defaultFlagToCached = async (flag: CompletableOptionFlag<any>) => {
   }
 }
 
-const defaultArgToCached = async (arg: Arg<any>) => {
+const defaultArgToCached = async (arg: Arg<any>): Promise<any> => {
   // Prefer the helpDefaultValue function (returns a friendly string for complex types)
   if (typeof arg.defaultHelp === 'function') {
     try {
diff --git a/src/util.ts b/src/util.ts
index 93fda3a0f..b3b4cdb36 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -98,11 +98,11 @@ export const fileExists = async (input: string): Promise<string> => {
 }
 
 export function isTruthy(input: string): boolean {
-  return ['true', 'TRUE', '1', 'yes', 'YES', 'y', 'Y'].includes(input)
+  return ['true', '1', 'yes', 'y'].includes(input.toLowerCase())
 }
 
 export function isNotFalsy(input: string): boolean {
-  return !['false', 'FALSE', '0', 'no', 'NO', 'n', 'N'].includes(input)
+  return !['false', '0', 'no', 'n'].includes(input.toLowerCase())
 }
 
 export function requireJson<T>(...pathParts: string[]): T {