diff --git a/zcash_primitives/src/pedersen_hash.rs b/zcash_primitives/src/pedersen_hash.rs
index 11dc387..835e9c7 100644
--- a/zcash_primitives/src/pedersen_hash.rs
+++ b/zcash_primitives/src/pedersen_hash.rs
@@ -5,7 +5,6 @@ use ff::{Field, PrimeField, PrimeFieldRepr};
 pub enum Personalization {
     NoteCommitment,
     MerkleTree(usize),
-    Empty,
 }
 
 impl Personalization {
@@ -17,9 +16,6 @@ impl Personalization {
 
                 (0..6).map(|i| (num >> i) & 1 == 1).collect()
             }
-            Personalization::Empty => {
-                vec![true, true, true, true, true, true]
-            }
         }
     }
 }
@@ -42,14 +38,12 @@ where
     let mut generators = params.pedersen_hash_exp_table().iter();
 
     loop {
-        // acc is <M_i>
         let mut acc = E::Fs::zero();
         let mut cur = E::Fs::one();
         let mut chunks_remaining = params.pedersen_hash_chunks_per_generator();
         let mut encountered_bits = false;
 
         // Grab three bits from the input
-        // spec: iterate over chunks (a,b,c)
         while let Some(a) = bits.next() {
             encountered_bits = true;
 
@@ -57,7 +51,6 @@ where
             let c = bits.next().unwrap_or(false);
 
             // Start computing this portion of the scalar
-            // tmp is enc(m_j)
             let mut tmp = cur;
             if a {
                 tmp.add_assign(&cur);
@@ -112,29 +105,3 @@ where
 
     result
 }
-
-#[cfg(test)]
-mod test {
-    use crate::{
-        jubjub::*,
-        pedersen_hash::{pedersen_hash, Personalization},
-    };
-    use pairing::bls12_381::{Bls12, Fr};
-
-    #[test]
-    fn test_pedersen_hash_noncircuit() {
-        let params = &JubjubBls12::new();
-        /*
-        for (i, generator) in params.pedersen_hash_generators().iter().enumerate() {
-            println!("generator {}, x={}, y={}", i, generator.to_xy().0, generator.to_xy().1)
-        }
-        */
-
-        let mut input: Vec<bool> = vec![];
-        for i in 0..(63*3*4+1) {
-            input.push(true);
-        }
-        let p = pedersen_hash::<Bls12, _>(Personalization::Empty, input, &params).to_xy();
-        println!("hash = {}, {}", p.0, p.1);
-    }
-}
diff --git a/zcash_proofs/src/circuit/pedersen_hash.rs b/zcash_proofs/src/circuit/pedersen_hash.rs
index 409f30e..acaf7c9 100644
--- a/zcash_proofs/src/circuit/pedersen_hash.rs
+++ b/zcash_proofs/src/circuit/pedersen_hash.rs
@@ -207,4 +207,57 @@ mod test {
             }
         }
     }
+
+    #[test]
+    fn test_pedersen_hash_external_test_vectors() {
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
+        let params = &JubjubBls12::new();
+
+        let expected_xs = [
+            "28161926966428986673895580777285905189725480206811328272001879986576840909576",
+            "39669831794597628158501766225645040955899576179071014703006420393381978263045",
+        ];
+        let expected_ys = [
+            "26869991781071974894722407757894142583682396277979904369818887810555917099932",
+            "2112827187110048608327330788910224944044097981650120385961435904443901436107",
+        ];
+        for length in 300..302 {
+            let mut input: Vec<bool> = (0..length).map(|_| rng.next_u32() % 2 != 0).collect();
+
+            let mut cs = TestConstraintSystem::<Bls12>::new();
+
+            let input_bools: Vec<Boolean> = input
+                .iter()
+                .enumerate()
+                .map(|(i, b)| {
+                    Boolean::from(
+                        AllocatedBit::alloc(cs.namespace(|| format!("input {}", i)), Some(*b))
+                            .unwrap(),
+                    )
+                })
+                .collect();
+
+            let res = pedersen_hash(
+                cs.namespace(|| "pedersen hash"),
+                Personalization::MerkleTree(1),
+                &input_bools,
+                params,
+            )
+            .unwrap();
+
+            assert!(cs.is_satisfied());
+
+            assert_eq!(
+                res.get_x().get_value().unwrap(),
+                Fr::from_str(expected_xs[length - 300]).unwrap()
+            );
+            assert_eq!(
+                res.get_y().get_value().unwrap(),
+                Fr::from_str(expected_ys[length - 300]).unwrap()
+            );
+        }
+    }
 }