diff --git a/src/circuit_tests/poseidon-hash-test.circom b/src/circuit_tests/poseidon-hash-test.circom
index 57a11e1..01b965e 100644
--- a/src/circuit_tests/poseidon-hash-test.circom
+++ b/src/circuit_tests/poseidon-hash-test.circom
@@ -1,3 +1,5 @@
+pragma circom 2.1.0;
+
 include "../../node_modules/circomlib/circuits/poseidon.circom";
 
 template PoseidonHash(SIZE) {