diff --git a/library/circuit.ts b/library/circuit.ts
index d4b3340..505b9b5 100644
--- a/library/circuit.ts
+++ b/library/circuit.ts
@@ -1,5 +1,7 @@
 import QuantumCircuit from 'quantum-circuit';
 
+declare module 'quantum-circuit';
+
 import { QuantumCircuitInterface } from './types/quantum-circuit';
 
 export class Circuit {