diff --git a/src/module/mod.rs b/src/module/mod.rs
index 143be2a5..b348058f 100644
--- a/src/module/mod.rs
+++ b/src/module/mod.rs
@@ -586,10 +586,10 @@ impl Module {
     ///
     /// assert_eq!(module.get_custom_type(name), Some("MyType"));
     /// ```
-    #[inline(always)]
+    #[inline]
     #[must_use]
     pub fn get_custom_type(&self, key: &str) -> Option<&str> {
-        self.custom_types.get(key)
+        self.custom_types.get(key).map(|t| t.display_name.as_str())
     }
 
     /// Returns `true` if this [`Module`] contains no items.
diff --git a/src/types/custom_types.rs b/src/types/custom_types.rs
index 4331d545..b0cb8bfd 100644
--- a/src/types/custom_types.rs
+++ b/src/types/custom_types.rs
@@ -3,14 +3,18 @@
 use crate::Identifier;
 use std::{any::type_name, collections::BTreeMap, fmt};
 
-/// _(internals)_ A custom type.
+/// _(internals)_ Information for a custom type.
 /// Exported under the `internals` feature only.
-pub type CustomType = Identifier;
+#[derive(Debug, Eq, PartialEq, Clone, Hash, Default)]
+pub struct CustomTypeInfo {
+    /// Friendly display name of the custom type.
+    pub display_name: Identifier,
+}
 
 /// _(internals)_ A collection of custom types.
 /// Exported under the `internals` feature only.
 #[derive(Clone, Hash, Default)]
-pub struct CustomTypesCollection(BTreeMap<Identifier, CustomType>);
+pub struct CustomTypesCollection(BTreeMap<Identifier, CustomTypeInfo>);
 
 impl fmt::Debug for CustomTypesCollection {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -33,21 +37,31 @@ impl CustomTypesCollection {
     /// Register a custom type.
     #[inline(always)]
     pub fn add(&mut self, type_name: impl Into<Identifier>, name: impl Into<Identifier>) {
-        self.add_raw(type_name, name.into());
+        self.add_raw(
+            type_name,
+            CustomTypeInfo {
+                display_name: name.into(),
+            },
+        );
     }
     /// Register a custom type.
     #[inline(always)]
     pub fn add_type<T>(&mut self, name: &str) {
-        self.add_raw(type_name::<T>(), name.into());
+        self.add_raw(
+            type_name::<T>(),
+            CustomTypeInfo {
+                display_name: name.into(),
+            },
+        );
     }
     /// Register a custom type.
     #[inline(always)]
-    pub fn add_raw(&mut self, type_name: impl Into<Identifier>, custom_type: CustomType) {
+    pub fn add_raw(&mut self, type_name: impl Into<Identifier>, custom_type: CustomTypeInfo) {
         self.0.insert(type_name.into(), custom_type);
     }
     /// Find a custom type.
     #[inline(always)]
-    pub fn get(&self, key: &str) -> Option<&str> {
-        self.0.get(key).map(CustomType::as_str)
+    pub fn get(&self, key: &str) -> Option<&CustomTypeInfo> {
+        self.0.get(key)
     }
 }
diff --git a/src/types/mod.rs b/src/types/mod.rs
index 6fad549e..6e2843e2 100644
--- a/src/types/mod.rs
+++ b/src/types/mod.rs
@@ -9,7 +9,7 @@ pub mod interner;
 pub mod parse_error;
 pub mod scope;
 
-pub use custom_types::{CustomType, CustomTypesCollection};
+pub use custom_types::{CustomTypeInfo, CustomTypesCollection};
 pub use dynamic::Dynamic;
 #[cfg(not(feature = "no_std"))]
 pub use dynamic::Instant;