diff --git a/crates/fayalite/src/annotations.rs b/crates/fayalite/src/annotations.rs
index 8eff4a0..1c517ae 100644
--- a/crates/fayalite/src/annotations.rs
+++ b/crates/fayalite/src/annotations.rs
@@ -12,7 +12,7 @@ use std::{
     ops::Deref,
 };
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 struct CustomFirrtlAnnotationFieldsImpl {
     value: serde_json::Map<String, serde_json::Value>,
     serialized: Interned<str>,
diff --git a/crates/fayalite/src/memory.rs b/crates/fayalite/src/memory.rs
index 1101157..622ffc6 100644
--- a/crates/fayalite/src/memory.rs
+++ b/crates/fayalite/src/memory.rs
@@ -470,7 +470,7 @@ pub enum ReadUnderWrite {
     Undefined,
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Hash)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
 struct MemImpl<Element: Type, Len: Size, P> {
     scoped_name: ScopedNameId,
     source_location: SourceLocation,
diff --git a/crates/fayalite/src/sim.rs b/crates/fayalite/src/sim.rs
index 563cd37..da7c293 100644
--- a/crates/fayalite/src/sim.rs
+++ b/crates/fayalite/src/sim.rs
@@ -5783,7 +5783,7 @@ where
     }
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
 struct SimTrace<K, S> {
     kind: K,
     state: S,