diff --git a/types/couchbase/couchbase-tests.ts b/types/couchbase/couchbase-tests.ts
index d04b71c907..e6ea7c12d3 100644
--- a/types/couchbase/couchbase-tests.ts
+++ b/types/couchbase/couchbase-tests.ts
@@ -31,6 +31,11 @@ bucket.manager().createPrimaryIndex(function() {
     });
 });
 
+// Ensure bucket.upsert is composable with normal callbacks
+function composable(callback: (err?: Error) => void) {
+    bucket.upsert('key', {value: 1}, callback);
+}
+
 // From https://developer.couchbase.com/documentation/server/current/sdk/nodejs/n1ql-queries-with-sdk.html
 function n1ql_a() {
     const n1qlquery = N1qlQuery.fromString('SELECT name, email FROM users WHERE name=$1');
diff --git a/types/couchbase/index.d.ts b/types/couchbase/index.d.ts
index f55ac6dbe9..813ee8f110 100644
--- a/types/couchbase/index.d.ts
+++ b/types/couchbase/index.d.ts
@@ -2019,10 +2019,10 @@ declare namespace Bucket {
      */
     interface OpCallback {
         /**
-         * @param error The error for the operation. This can either be an Error object or a value which evaluates to false (null, undefined, 0 or false).
+         * @param error The error for the operation. This can either be an Error object or a value which evaluates to false.
          * @param result The result of the operation that was executed. This usually contains at least a cas property, and on some operations will contain a value property as well.
          */
-        (error: CouchbaseError | number, result: any): void;
+        (error: CouchbaseError | null, result: any): void;
     }
 
     /**