diff --git a/types/redis/index.d.ts b/types/redis/index.d.ts
index ff071e43e4..b838fcc1e9 100644
--- a/types/redis/index.d.ts
+++ b/types/redis/index.d.ts
@@ -1025,8 +1025,8 @@ export interface Commands<R> {
     /**
      * Increment the score of a member in a sorted set.
      */
-    zincrby(key: string, increment: number, member: string, cb?: Callback<number>): R;
-    ZINCRBY(key: string, increment: number, member: string, cb?: Callback<number>): R;
+    zincrby(key: string, increment: number, member: string, cb?: Callback<string>): R;
+    ZINCRBY(key: string, increment: number, member: string, cb?: Callback<string>): R;
 
     /**
      * Intersect multiple sorted sets and store the resulting sorted set in a new key.
diff --git a/types/redis/redis-tests.ts b/types/redis/redis-tests.ts
index 18b9e11203..5d7d617b91 100644
--- a/types/redis/redis-tests.ts
+++ b/types/redis/redis-tests.ts
@@ -131,3 +131,5 @@ client.incrbyfloat('a', 1.5, (error, value) => value.startsWith('1'));
 client.INCRBYFLOAT('a', 1.5, (error, value) => value.startsWith('1'));
 client.hincrbyfloat('a', 'b', 1.5, (error, value) => value.startsWith('1'));
 client.HINCRBYFLOAT('a', 'b', 1.5, (error, value) => value.startsWith('1'));
+client.zincrby('a', 1, 'b', strCallback);
+client.ZINCRBY('a', 1, 'b', strCallback);