diff --git a/crypto-primitives/src/commitment/blake2s/constraints.rs b/crypto-primitives/src/commitment/blake2s/constraints.rs
index fd4c04e..660a2fd 100644
--- a/crypto-primitives/src/commitment/blake2s/constraints.rs
+++ b/crypto-primitives/src/commitment/blake2s/constraints.rs
@@ -3,7 +3,7 @@ use r1cs_core::{ConstraintSystem, SynthesisError};
 use crate::{
     commitment::blake2s::Blake2sCommitment,
     prf::blake2s::constraints::{blake2s_gadget, Blake2sOutputGadget},
-    CommitmentGadget,
+    CommitmentGadget, Vec,
 };
 use algebra_core::{Field, PrimeField};
 use r1cs_std::prelude::*;
diff --git a/crypto-primitives/src/commitment/pedersen/constraints.rs b/crypto-primitives/src/commitment/pedersen/constraints.rs
index 3b591e8..ffa54b9 100644
--- a/crypto-primitives/src/commitment/pedersen/constraints.rs
+++ b/crypto-primitives/src/commitment/pedersen/constraints.rs
@@ -1,6 +1,7 @@
 use crate::{
     commitment::pedersen::{PedersenCommitment, PedersenParameters, PedersenRandomness},
     crh::pedersen::PedersenWindow,
+    Vec,
 };
 use algebra_core::{
     fields::{Field, PrimeField},
diff --git a/crypto-primitives/src/crh/bowe_hopwood/constraints.rs b/crypto-primitives/src/crh/bowe_hopwood/constraints.rs
index 5a077ec..b16f1a3 100644
--- a/crypto-primitives/src/crh/bowe_hopwood/constraints.rs
+++ b/crypto-primitives/src/crh/bowe_hopwood/constraints.rs
@@ -1,9 +1,12 @@
 use core::{borrow::Borrow, hash::Hash, marker::PhantomData};
 
-use crate::crh::{
-    bowe_hopwood::{BoweHopwoodPedersenCRH, BoweHopwoodPedersenParameters, CHUNK_SIZE},
-    pedersen::PedersenWindow,
-    FixedLengthCRHGadget,
+use crate::{
+    crh::{
+        bowe_hopwood::{BoweHopwoodPedersenCRH, BoweHopwoodPedersenParameters, CHUNK_SIZE},
+        pedersen::PedersenWindow,
+        FixedLengthCRHGadget,
+    },
+    Vec,
 };
 use algebra_core::{groups::Group, Field};
 use r1cs_core::{ConstraintSystem, SynthesisError};
diff --git a/crypto-primitives/src/crh/pedersen/constraints.rs b/crypto-primitives/src/crh/pedersen/constraints.rs
index 4404e2d..6048adc 100644
--- a/crypto-primitives/src/crh/pedersen/constraints.rs
+++ b/crypto-primitives/src/crh/pedersen/constraints.rs
@@ -1,6 +1,9 @@
-use crate::crh::{
-    pedersen::{PedersenCRH, PedersenParameters, PedersenWindow},
-    FixedLengthCRHGadget,
+use crate::{
+    crh::{
+        pedersen::{PedersenCRH, PedersenParameters, PedersenWindow},
+        FixedLengthCRHGadget,
+    },
+    Vec,
 };
 use algebra_core::{Field, Group};
 use r1cs_core::{ConstraintSystem, SynthesisError};
diff --git a/crypto-primitives/src/nizk/gm17/constraints.rs b/crypto-primitives/src/nizk/gm17/constraints.rs
index dc95a8a..1604be0 100644
--- a/crypto-primitives/src/nizk/gm17/constraints.rs
+++ b/crypto-primitives/src/nizk/gm17/constraints.rs
@@ -1,4 +1,7 @@
-use crate::nizk::{gm17::Gm17, NIZKVerifierGadget};
+use crate::{
+    nizk::{gm17::Gm17, NIZKVerifierGadget},
+    Vec,
+};
 use algebra_core::{AffineCurve, Field, PairingEngine, ToConstraintField};
 use r1cs_core::{ConstraintSynthesizer, ConstraintSystem, SynthesisError};
 use r1cs_std::prelude::*;
diff --git a/crypto-primitives/src/nizk/groth16/constraints.rs b/crypto-primitives/src/nizk/groth16/constraints.rs
index e238185..71907dd 100644
--- a/crypto-primitives/src/nizk/groth16/constraints.rs
+++ b/crypto-primitives/src/nizk/groth16/constraints.rs
@@ -1,4 +1,7 @@
-use crate::nizk::{groth16::Groth16, NIZKVerifierGadget};
+use crate::{
+    nizk::{groth16::Groth16, NIZKVerifierGadget},
+    Vec,
+};
 use algebra_core::{AffineCurve, Field, PairingEngine, ToConstraintField};
 use r1cs_core::{ConstraintSynthesizer, ConstraintSystem, SynthesisError};
 use r1cs_std::prelude::*;
diff --git a/crypto-primitives/src/prf/blake2s/constraints.rs b/crypto-primitives/src/prf/blake2s/constraints.rs
index 7695f4c..cd1d3b2 100644
--- a/crypto-primitives/src/prf/blake2s/constraints.rs
+++ b/crypto-primitives/src/prf/blake2s/constraints.rs
@@ -1,7 +1,7 @@
 use algebra_core::PrimeField;
 use r1cs_core::{ConstraintSystem, SynthesisError};
 
-use crate::prf::PRFGadget;
+use crate::{prf::PRFGadget, Vec};
 use r1cs_std::prelude::*;
 
 use core::borrow::Borrow;
diff --git a/crypto-primitives/src/prf/constraints.rs b/crypto-primitives/src/prf/constraints.rs
index ef2befa..69de337 100644
--- a/crypto-primitives/src/prf/constraints.rs
+++ b/crypto-primitives/src/prf/constraints.rs
@@ -1,7 +1,7 @@
 use algebra_core::Field;
 use core::fmt::Debug;
 
-use crate::prf::PRF;
+use crate::{prf::PRF, Vec};
 use r1cs_core::{ConstraintSystem, SynthesisError};
 
 use r1cs_std::prelude::*;
diff --git a/crypto-primitives/src/signature/schnorr/constraints.rs b/crypto-primitives/src/signature/schnorr/constraints.rs
index 5790659..f9d8ad8 100644
--- a/crypto-primitives/src/signature/schnorr/constraints.rs
+++ b/crypto-primitives/src/signature/schnorr/constraints.rs
@@ -1,3 +1,4 @@
+use crate::Vec;
 use algebra_core::{groups::Group, Field};
 use r1cs_core::{ConstraintSystem, SynthesisError};
 use r1cs_std::prelude::*;