diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..539cbd4
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,28 @@
+declare module 'datasource-sql' {
+    import * as knex from 'knex'
+
+    // attempt at fixing the undefined function 'cache' on QueryBuilder - doesn't improve the situation
+    //
+    // interface QueryBuilderEx<TRecord extends {} = any, TResult = any> 
+    //   extends QueryBuilder<TRecord, TResult> {
+    //     cache(ttl: number): this;
+    // }
+    // interface KnexEx<TRecord extends {} = any, TResult = unknown[]>
+    //   extends knex<TRecord, TResult> {
+    //     <TRecord2 = TRecord, TResult2 = DeferredKeySelection<TRecord2, never>[]>(
+    //         tableName?: Knex.TableDescriptor | Knex.AliasDict,
+    //         options?: TableOptions
+    //     ): QueryBuilderEx<TRecord2, TResult2>;
+    // }
+
+    export class SQLDataSource {
+        knex: knex
+        // for above attempt - knex: KnexEx
+        
+        constructor(...args: any[]);
+
+        cacheQuery(...args: any[]): void;
+
+        initialize(...args: any[]): void;
+    }
+}