diff --git a/linera-base/src/identifiers.rs b/linera-base/src/identifiers.rs
index 2b46e5bc26a6..7846240da87b 100644
--- a/linera-base/src/identifiers.rs
+++ b/linera-base/src/identifiers.rs
@@ -30,7 +30,7 @@ use crate::{
 };
 
 /// An account owner.
-#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd, WitLoad, WitStore, WitType)]
+#[derive(Clone, Copy, Eq, Hash, Ord, PartialEq, PartialOrd, WitLoad, WitStore, WitType)]
 #[cfg_attr(with_testing, derive(test_strategy::Arbitrary))]
 pub enum AccountOwner {
     /// Short addresses reserved for the protocol.
@@ -38,10 +38,19 @@ pub enum AccountOwner {
     /// 32-byte account address.
     Address32(CryptoHash),
     /// 20-byte account EVM-compatible address.
-    #[debug(with = "hex_debug")]
     Address20([u8; 20]),
 }
 
+impl fmt::Debug for AccountOwner {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Reserved(byte) => f.debug_tuple("Reserved").field(byte).finish(),
+            Self::Address32(hash) => write!(f, "Address32({:?}..)", hash),
+            Self::Address20(bytes) => write!(f, "Address20({}..)", hex::encode(&bytes[..8])),
+        }
+    }
+}
+
 impl AccountOwner {
     /// Returns the default chain address.
     pub const CHAIN: AccountOwner = AccountOwner::Reserved(0);
diff --git a/linera-base/src/unit_tests.rs b/linera-base/src/unit_tests.rs
index 92962ab8a8fa..4a2d901f9502 100644
--- a/linera-base/src/unit_tests.rs
+++ b/linera-base/src/unit_tests.rs
@@ -155,3 +155,14 @@ fn chain_ownership_test_case() -> ChainOwnership {
         },
     }
 }
+
+#[test]
+fn account_owner_debug_format() {
+    assert_eq!(&format!("{:?}", AccountOwner::Reserved(10)), "Reserved(10)");
+    let addr32 = AccountOwner::Address32(CryptoHash::from([10u8; 32]));
+    let debug32 = "Address32(0a0a0a0a0a0a0a0a..)";
+    assert_eq!(&format!("{addr32:?}"), debug32);
+    let addr20 = AccountOwner::Address20([10u8; 20]);
+    let debug20 = "Address20(0a0a0a0a0a0a0a0a..)";
+    assert_eq!(&format!("{addr20:?}"), debug20);
+}