diff --git a/zebra-chain/proptest-regressions/keys/sapling/tests.txt b/zebra-chain/proptest-regressions/keys/sapling/tests.txt
new file mode 100644
index 00000000..313f3bba
--- /dev/null
+++ b/zebra-chain/proptest-regressions/keys/sapling/tests.txt
@@ -0,0 +1,7 @@
+# Seeds for failure cases proptest has generated in the past. It is
+# automatically read and these particular cases re-run before any
+# novel cases are generated.
+#
+# It is recommended to check this file in to source control so that
+# everyone who runs the test benefits from these saved cases.
+cc 14cc005b0333245bcb502328cfdad9a44032fe7b3fb38a8a17c2eaa10b26dd38 # shrinks to spending_key = SpendingKey { network: Mainnet, bytes: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] }
diff --git a/zebra-chain/src/keys/sapling.rs b/zebra-chain/src/keys/sapling.rs
index 6fe12719..2352c3b0 100644
--- a/zebra-chain/src/keys/sapling.rs
+++ b/zebra-chain/src/keys/sapling.rs
@@ -182,6 +182,7 @@ mod sk_hrp {
 ///
 /// [ps]: https://zips.z.cash/protocol/protocol.pdf#saplingkeycomponents
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[cfg_attr(test, derive(Arbitrary))]
 pub struct SpendingKey {
     network: Network,
     bytes: [u8; 32],
@@ -223,7 +224,7 @@ impl FromStr for SpendingKey {
 
                 Ok(SpendingKey {
                     network: match hrp.as_str() {
-                        ivk_hrp::MAINNET => Network::Mainnet,
+                        sk_hrp::MAINNET => Network::Mainnet,
                         _ => Network::Testnet,
                     },
                     bytes: decoded_bytes,
@@ -713,8 +714,6 @@ impl Diversifier {
 #[derive(Copy, Clone, PartialEq)]
 pub struct TransmissionKey(pub jubjub::AffinePoint);
 
-impl Eq for TransmissionKey {}
-
 impl Deref for TransmissionKey {
     type Target = jubjub::AffinePoint;
 
@@ -732,6 +731,8 @@ impl fmt::Debug for TransmissionKey {
     }
 }
 
+impl Eq for TransmissionKey {}
+
 impl TransmissionKey {
     /// This includes _KA^Sapling.DerivePublic(ivk, G_d)_, which is just a
     /// scalar mult _[ivk]G_d_.
diff --git a/zebra-chain/src/keys/sapling/tests.rs b/zebra-chain/src/keys/sapling/tests.rs
index eb00964a..a2fafbb3 100644
--- a/zebra-chain/src/keys/sapling/tests.rs
+++ b/zebra-chain/src/keys/sapling/tests.rs
@@ -1,8 +1,8 @@
+use super::*;
+
 #[cfg(test)]
 use proptest::{array, prelude::*};
 
-use super::*;
-
 #[cfg(test)]
 impl Arbitrary for TransmissionKey {
     type Parameters = ();
@@ -95,6 +95,29 @@ mod tests {
 #[cfg(test)]
 proptest! {
 
-    //#[test]
-    // fn test() {}
+    #[test]
+    fn string_roundtrips(spending_key in any::<SpendingKey>()) {
+        let sk_string = spending_key.to_string();
+        let spending_key_2: SpendingKey = sk_string.parse().unwrap();
+        prop_assert_eq![spending_key, spending_key_2];
+
+        let spend_authorizing_key = SpendAuthorizingKey::from(spending_key);
+        let proof_authorizing_key = ProofAuthorizingKey::from(spending_key);
+        let outgoing_viewing_key = OutgoingViewingKey::from(spending_key);
+
+        let authorizing_key = AuthorizingKey::from(spend_authorizing_key);
+        let nullifier_deriving_key = NullifierDerivingKey::from(proof_authorizing_key);
+        let incoming_viewing_key =
+            IncomingViewingKey::from((authorizing_key, nullifier_deriving_key));
+
+        // let diversifier = Diversifier::from(spending_key);
+        // let transmission_key = TransmissionKey::from(incoming_viewing_key, diversifier);
+
+
+        let string = incoming_viewing_key.to_string();
+        let incoming_viewing_key_2 = string.parse::<IncomingViewingKey>().unwrap();
+
+        prop_assert_eq![incoming_viewing_key, incoming_viewing_key_2];
+
+    }
 }
diff --git a/zebra-chain/src/keys/sprout.rs b/zebra-chain/src/keys/sprout.rs
index 9b2faa74..3d31206a 100644
--- a/zebra-chain/src/keys/sprout.rs
+++ b/zebra-chain/src/keys/sprout.rs
@@ -336,7 +336,7 @@ proptest! {
 
         let mut data = Vec::new();
 
-        sk.zcash_serialize(&mut data).expect("sprout spending keyshould serialize");
+        sk.zcash_serialize(&mut data).expect("sprout spending key should serialize");
 
         let sk2 = SpendingKey::zcash_deserialize(&data[..]).expect("randomized sprout spending key should deserialize");
 
@@ -360,7 +360,7 @@ proptest! {
 
         let mut data = Vec::new();
 
-        ivk.zcash_serialize(&mut data).expect("t-addr should serialize");
+        ivk.zcash_serialize(&mut data).expect("sprout z-addr should serialize");
 
         let ivk2 = IncomingViewingKey::zcash_deserialize(&data[..]).expect("randomized ivk should deserialize");