diff --git a/units/tests/str.rs b/units/tests/str.rs
index 767ed6a9f..98e06f72e 100644
--- a/units/tests/str.rs
+++ b/units/tests/str.rs
@@ -3,6 +3,7 @@
 //! Do basic regression tests on the `Display` and `FromStr` impls.
 
 use bitcoin_units::locktime::{absolute, relative};
+use bitcoin_units::amount::Denomination;
 use bitcoin_units::{Amount, BlockHeight, BlockInterval, FeeRate, SignedAmount, Weight};
 
 macro_rules! check {
@@ -24,6 +25,9 @@ check! {
     amount_unsigned_one_sat, Amount, Amount::ONE_SAT, "0.00000001 BTC";
     amount_unsigned_max_money, Amount, Amount::MAX, "21000000 BTC";
 
+    denomination_btc, Denomination, Denomination::BTC, "BTC";
+    denomination_sat, Denomination, Denomination::SAT, "satoshi";
+
     amount_signed_one_sat, SignedAmount, SignedAmount::ONE_SAT, "0.00000001 BTC";
     amount_signed_max_money, SignedAmount, SignedAmount::MAX, "21000000 BTC";
 
@@ -43,6 +47,12 @@ check! {
     lock_by_height_relative_min, relative::Height, relative::Height::MIN, "0";
     lock_by_height_relative_max, relative::Height, relative::Height::MAX, "65535";
 
+    lock_by_time_absolute_min, absolute::Time, absolute::Time::MIN, "500000000";
+    lock_by_time_absolute_max, absolute::Time, absolute::Time::MAX, "4294967295";
+
+    lock_by_time_relative_min, relative::Time, relative::Time::MIN, "0";
+    lock_by_time_relative_max, relative::Time, relative::Time::MAX, "65535";
+
     weight_min, Weight, Weight::MIN, "0";
     weight_max, Weight, Weight::MAX, "18446744073709551615";
     weight_max_block, Weight, Weight::MAX_BLOCK, "4000000";