diff --git a/src/CacheProvider.ts b/src/CacheProvider.ts
index 5331868..c957667 100644
--- a/src/CacheProvider.ts
+++ b/src/CacheProvider.ts
@@ -1,5 +1,5 @@
 export default interface CacheProvider {
-    get(key: string, defaultValue?: string): Promise<string | null>;
+    get<T extends string | undefined>(key: string, defaultValue?: T): Promise<T>;
 
     has(key: string): Promise<boolean>;
 
diff --git a/src/components/RedisComponent.ts b/src/components/RedisComponent.ts
index 996f1eb..aad7e7d 100644
--- a/src/components/RedisComponent.ts
+++ b/src/components/RedisComponent.ts
@@ -42,8 +42,8 @@ export default class RedisComponent extends ApplicationComponent implements Cach
         return this.redisClient !== undefined && this.redisClient.connected;
     }
 
-    public async get(key: string, defaultValue?: string): Promise<string | null> {
-        return await new Promise<string | null>((resolve, reject) => {
+    public async get<T extends string | undefined>(key: string, defaultValue?: T): Promise<T> {
+        return await new Promise<T>((resolve, reject) => {
             if (!this.redisClient) {
                 reject(`Redis store was not initialized.`);
                 return;
@@ -54,13 +54,13 @@ export default class RedisComponent extends ApplicationComponent implements Cach
                     reject(err);
                     return;
                 }
-                resolve(val || defaultValue || null);
+                resolve((val || defaultValue || undefined) as T);
             });
         });
     }
 
     public async has(key: string): Promise<boolean> {
-        return await this.get(key) !== null;
+        return await this.get(key) !== undefined;
     }
 
     public async forget(key: string): Promise<void> {