diff --git a/src/ast.rs b/src/ast.rs
index d3d0e267..c5409298 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -66,11 +66,6 @@ pub struct ScriptFnDef {
     pub access: FnAccess,
     /// Names of function parameters.
     pub params: StaticVec<Identifier>,
-    /// Access to external variables.
-    ///
-    /// Not available under `no_closure`.
-    #[cfg(not(feature = "no_closure"))]
-    pub externals: std::collections::BTreeSet<Identifier>,
     /// _(metadata)_ Function doc-comments (if any).
     /// Exported under the `metadata` feature only.
     ///
diff --git a/src/optimize.rs b/src/optimize.rs
index 7bed6a15..12699422 100644
--- a/src/optimize.rs
+++ b/src/optimize.rs
@@ -1160,8 +1160,6 @@ pub fn optimize_into_ast(
                     access: fn_def.access,
                     body: crate::ast::StmtBlock::empty(),
                     params: fn_def.params.clone(),
-                    #[cfg(not(feature = "no_closure"))]
-                    externals: fn_def.externals.clone(),
                     lib: None,
                     #[cfg(not(feature = "no_module"))]
                     mods: crate::engine::Imports::new(),
diff --git a/src/parse.rs b/src/parse.rs
index daf8aab1..3d1f8a71 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -3068,21 +3068,10 @@ fn parse_fn(
     let mut params: StaticVec<_> = params.into_iter().map(|(p, _)| p).collect();
     params.shrink_to_fit();
 
-    #[cfg(not(feature = "no_closure"))]
-    let externals = state
-        .external_vars
-        .iter()
-        .map(|(name, _)| name)
-        .filter(|name| !params.contains(name))
-        .cloned()
-        .collect();
-
     Ok(ScriptFnDef {
         name: state.get_identifier(name),
         access,
         params,
-        #[cfg(not(feature = "no_closure"))]
-        externals,
         body,
         lib: None,
         #[cfg(not(feature = "no_module"))]
@@ -3228,8 +3217,6 @@ fn parse_anon_fn(
         name: fn_name.clone(),
         access: FnAccess::Public,
         params,
-        #[cfg(not(feature = "no_closure"))]
-        externals: std::collections::BTreeSet::new(),
         body: body.into(),
         lib: None,
         #[cfg(not(feature = "no_module"))]