diff --git a/crypto/dalek-ff-group/src/field.rs b/crypto/dalek-ff-group/src/field.rs
index b874c871..527e187f 100644
--- a/crypto/dalek-ff-group/src/field.rs
+++ b/crypto/dalek-ff-group/src/field.rs
@@ -207,8 +207,8 @@ impl FieldElement {
 #[test]
 fn test_conditional_negate() {
   let one = FieldElement::one();
-  let true_choice = choice(true);
-  let false_choice = choice(false);
+  let true_choice = 1.into();
+  let false_choice = 0.into();
 
   let mut var = one;
 
diff --git a/crypto/dalek-ff-group/src/lib.rs b/crypto/dalek-ff-group/src/lib.rs
index 44efedfa..31c8edae 100644
--- a/crypto/dalek-ff-group/src/lib.rs
+++ b/crypto/dalek-ff-group/src/lib.rs
@@ -244,7 +244,7 @@ impl PrimeField for Scalar {
 
   const S: u32 = 2;
   fn is_odd(&self) -> Choice {
-    unimplemented!()
+    choice(self.to_le_bits()[0])
   }
   fn multiplicative_generator() -> Self {
     2u64.into()
diff --git a/crypto/ed448/Cargo.toml b/crypto/ed448/Cargo.toml
index c25b8a2a..945e529f 100644
--- a/crypto/ed448/Cargo.toml
+++ b/crypto/ed448/Cargo.toml
@@ -22,7 +22,7 @@ ff = "0.12"
 group = "0.12"
 
 generic-array = "0.14"
-crypto-bigint = {version = "0.4", features = ["zeroize"] }
+crypto-bigint = { version = "0.4", features = ["zeroize"] }
 
 dalek-ff-group = { path = "../dalek-ff-group", version = "^0.1.2" }