diff --git a/zcash_primitives/src/note_encryption.rs b/zcash_primitives/src/note_encryption.rs
index cf0b446e0..e6a64f061 100644
--- a/zcash_primitives/src/note_encryption.rs
+++ b/zcash_primitives/src/note_encryption.rs
@@ -381,8 +381,7 @@ fn parse_note_plaintext_without_memo<P: consensus::Parameters>(
         return None;
     }
 
-    if let Rseed::AfterZip212(_) = note.rseed {
-        let derived_esk = note.derive_esk().unwrap();
+    if let Some(derived_esk) = note.derive_esk() {
         if note.g_d.mul(derived_esk, &JUBJUB) != *epk {
             return None;
         }
@@ -461,7 +460,7 @@ pub fn try_sapling_note_decryption<P: consensus::Parameters>(
 ///
 /// Implements the procedure specified in [`ZIP 307`].
 ///
-/// [`ZIP 307`]: https://github.com/zcash/zips/pull/226
+/// [`ZIP 307`]: https://zips.z.cash/zip-0307
 pub fn try_sapling_compact_note_decryption<P: consensus::Parameters>(
     height: u32,
     ivk: &Fs,
@@ -580,8 +579,8 @@ pub fn try_sapling_output_recovery<P: consensus::Parameters>(
         return None;
     }
 
-    if let Rseed::AfterZip212(_) = note.rseed {
-        if note.derive_esk().unwrap() != esk {
+    if let Some(derived_esk) = note.derive_esk() {
+        if derived_esk != esk {
             return None;
         }
     }
diff --git a/zcash_primitives/src/primitives.rs b/zcash_primitives/src/primitives.rs
index bb5b2e1c9..e475bd7ce 100644
--- a/zcash_primitives/src/primitives.rs
+++ b/zcash_primitives/src/primitives.rs
@@ -337,8 +337,8 @@ impl<E: JubjubEngine> Note<E> {
     }
 
     pub fn generate_or_derive_esk<R: RngCore + CryptoRng>(&self, rng: &mut R) -> E::Fs {
-        match self.rseed {
-            Rseed::BeforeZip212(_) => {
+        match self.derive_esk() {
+            None => {
                 // create random 64 byte buffer
                 let mut buffer = [0u8; 64];
                 &rng.fill_bytes(&mut buffer);
@@ -346,7 +346,7 @@ impl<E: JubjubEngine> Note<E> {
                 // reduce to uniform value
                 E::Fs::to_uniform(&buffer[..])
             }
-            Rseed::AfterZip212(_) => self.derive_esk().unwrap(),
+            Some(esk) => esk,
         }
     }