diff --git a/zebra-chain/src/block/tests.rs b/zebra-chain/src/block/tests.rs
index 1e662bbb9..85fffb626 100644
--- a/zebra-chain/src/block/tests.rs
+++ b/zebra-chain/src/block/tests.rs
@@ -3,8 +3,6 @@ use std::io::{Cursor, Write};
 use chrono::NaiveDateTime;
 use proptest::{
     arbitrary::{any, Arbitrary},
-    collection::vec,
-    option,
     prelude::*,
 };
 
diff --git a/zebra-chain/src/equihash_solution.rs b/zebra-chain/src/equihash_solution.rs
index af1ef59c1..44cc37236 100644
--- a/zebra-chain/src/equihash_solution.rs
+++ b/zebra-chain/src/equihash_solution.rs
@@ -20,12 +20,6 @@ const EQUIHASH_SOLUTION_SIZE: usize = 1344;
 /// length of this type is fixed.
 pub struct EquihashSolution(pub [u8; EQUIHASH_SOLUTION_SIZE]);
 
-impl Default for EquihashSolution {
-    fn default() -> Self {
-        EquihashSolution([0; EQUIHASH_SOLUTION_SIZE])
-    }
-}
-
 impl PartialEq<EquihashSolution> for EquihashSolution {
     fn eq(&self, other: &EquihashSolution) -> bool {
         self.0.as_ref() == other.0.as_ref()
@@ -87,18 +81,24 @@ impl Arbitrary for EquihashSolution {
 }
 
 #[cfg(test)]
-proptest! {
+mod tests {
 
-    #[test]
-    fn encrypted_ciphertext_roundtrip(solution in any::<EquihashSolution>()) {
+    use super::*;
 
-        let mut data = Vec::new();
+    proptest! {
 
-        solution.zcash_serialize(&mut data).expect("EquihashSolution should serialize");
+        #[test]
+        fn equihash_solution_roundtrip(solution in any::<EquihashSolution>()) {
 
-        let solution2 = EquihashSolution::zcash_deserialize(&data[..]).expect("randomized EquihashSolution should deserialize");
+            let mut data = Vec::new();
+
+            solution.zcash_serialize(&mut data).expect("EquihashSolution should serialize");
+
+            let solution2 = EquihashSolution::zcash_deserialize(&data[..])
+                .expect("randomized EquihashSolution should deserialize");
+
+            prop_assert_eq![solution, solution2];
+        }
 
-        prop_assert_eq![solution, solution2];
     }
-
 }