diff --git a/src/interpreter/env_native.rs b/src/interpreter/env_native.rs
index 953a40e..053fa31 100644
--- a/src/interpreter/env_native.rs
+++ b/src/interpreter/env_native.rs
@@ -26,7 +26,9 @@ pub trait UserFunctionExecutor {
 /// User function descriptor
 #[derive(Clone)]
 pub enum UserFunctionDescriptor {
+	/// Static function definition
 	Static(&'static str, &'static [ValueType]),
+	/// Dynamic heap function definition
 	Heap(String, Vec<ValueType>),
 }
 
diff --git a/src/interpreter/mod.rs b/src/interpreter/mod.rs
index 7d3331a..33155bd 100644
--- a/src/interpreter/mod.rs
+++ b/src/interpreter/mod.rs
@@ -79,5 +79,5 @@ pub use self::table::TableInstance;
 pub use self::program::ProgramInstance;
 pub use self::value::RuntimeValue;
 pub use self::variable::VariableInstance;
-pub use self::env_native::{env_native_module, UserFunctions, UserFunction, UserFunctionExecutor};
+pub use self::env_native::{env_native_module, UserFunctions, UserFunction, UserFunctionExecutor, UserFunctionDescriptor};
 pub use self::env::EnvParams;
\ No newline at end of file