diff --git a/src/snark/libsnark/gadgetlib1/gadgets/basic_gadgets.tcc b/src/snark/libsnark/gadgetlib1/gadgets/basic_gadgets.tcc
index 46db45532..4e2d9fce3 100644
--- a/src/snark/libsnark/gadgetlib1/gadgets/basic_gadgets.tcc
+++ b/src/snark/libsnark/gadgetlib1/gadgets/basic_gadgets.tcc
@@ -585,7 +585,7 @@ void loose_multiplexing_gadget<FieldT>::generate_r1cs_constraints()
 template<typename FieldT>
 void loose_multiplexing_gadget<FieldT>::generate_r1cs_witness()
 {
-    /* assumes that idx can be fit in ulong; true for our purposes for now */
+    /* assumes that idx can be fit in uint64_t; true for our purposes for now */
     const bigint<FieldT::num_limbs> valint = this->pb.val(index).as_bigint();
     uint64_t idx = valint.as_uint64();
     const bigint<FieldT::num_limbs> arrsize(arr.size());