diff --git a/CHANGELOG.md b/CHANGELOG.md
index e53f2148..2ebebf9d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ Breaking changes
 * `ModuleResolver` trait methods take an additional parameter `source_path` that contains the path of the current environment. This is to facilitate loading other script files always from the current directory.
 * `FileModuleResolver` now resolves relative paths under the source path if there is no base path set.
 * `FileModuleResolver::base_path` now returns `Option<&str>` which is `None` if there is no base path set.
+* Doc-comments now require the `metadata` feature.
 
 New features
 ------------
diff --git a/src/ast.rs b/src/ast.rs
index 9d7902d8..d7b50786 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -11,7 +11,6 @@ use crate::stdlib::{
     iter::empty,
     num::{NonZeroU8, NonZeroUsize},
     ops::{Add, AddAssign},
-    string::String,
     vec,
     vec::Vec,
 };
@@ -65,7 +64,9 @@ pub struct ScriptFnDef {
     #[cfg(not(feature = "no_closure"))]
     pub externals: crate::stdlib::collections::BTreeSet<Identifier>,
     /// Function doc-comments (if any).
-    pub comments: StaticVec<String>,
+    #[cfg(not(feature = "no_function"))]
+    #[cfg(feature = "metadata")]
+    pub comments: StaticVec<crate::stdlib::string::String>,
 }
 
 impl fmt::Display for ScriptFnDef {
@@ -103,6 +104,8 @@ pub struct ScriptFnMetadata<'a> {
     ///
     /// Leading white-spaces are stripped, and each string slice always starts with the corresponding
     /// doc-comment leader: `///` or `/**`.
+    #[cfg(not(feature = "no_function"))]
+    #[cfg(feature = "metadata")]
     pub comments: Vec<&'a str>,
     /// Function access mode.
     pub access: FnAccess,
@@ -134,6 +137,8 @@ impl<'a> Into<ScriptFnMetadata<'a>> for &'a ScriptFnDef {
     #[inline(always)]
     fn into(self) -> ScriptFnMetadata<'a> {
         ScriptFnMetadata {
+            #[cfg(not(feature = "no_function"))]
+            #[cfg(feature = "metadata")]
             comments: self.comments.iter().map(|s| s.as_str()).collect(),
             access: self.access,
             name: &self.name,
diff --git a/src/optimize.rs b/src/optimize.rs
index 03814584..7e4bcb88 100644
--- a/src/optimize.rs
+++ b/src/optimize.rs
@@ -1002,6 +1002,8 @@ pub fn optimize_into_ast(
                     lib: None,
                     #[cfg(not(feature = "no_module"))]
                     mods: Default::default(),
+                    #[cfg(not(feature = "no_function"))]
+                    #[cfg(feature = "metadata")]
                     comments: Default::default(),
                 })
                 .for_each(|fn_def| {
diff --git a/src/parser.rs b/src/parser.rs
index ab0aa0bc..9bac4053 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -16,7 +16,7 @@ use crate::stdlib::{
     hash::{Hash, Hasher},
     iter::empty,
     num::{NonZeroU8, NonZeroUsize},
-    string::{String, ToString},
+    string::ToString,
     vec,
     vec::Vec,
 };
@@ -2483,10 +2483,10 @@ fn parse_stmt(
 ) -> Result<Stmt, ParseError> {
     use AccessMode::{ReadOnly, ReadWrite};
 
-    let mut _comments: StaticVec<String> = Default::default();
-
     #[cfg(not(feature = "no_function"))]
-    {
+    #[cfg(feature = "metadata")]
+    let comments = {
+        let mut comments: StaticVec<crate::stdlib::string::String> = Default::default();
         let mut comments_pos = Position::NONE;
 
         // Handle doc-comments.
@@ -2505,7 +2505,7 @@ fn parse_stmt(
 
             match input.next().unwrap().0 {
                 Token::Comment(comment) => {
-                    _comments.push(comment);
+                    comments.push(comment);
 
                     match input.peek().unwrap() {
                         (Token::Fn, _) | (Token::Private, _) => break,
@@ -2516,7 +2516,9 @@ fn parse_stmt(
                 _ => unreachable!(),
             }
         }
-    }
+
+        comments
+    };
 
     let (token, token_pos) = match input.peek().unwrap() {
         (Token::EOF, pos) => return Ok(Stmt::Noop(*pos)),
@@ -2572,7 +2574,17 @@ fn parse_stmt(
                         pos: pos,
                     };
 
-                    let func = parse_fn(input, &mut new_state, lib, access, settings, _comments)?;
+                    let func = parse_fn(
+                        input,
+                        &mut new_state,
+                        lib,
+                        access,
+                        settings,
+                        #[cfg(not(feature = "no_function"))]
+                        #[cfg(feature = "metadata")]
+                        comments,
+                    )?;
+
                     let hash = calc_fn_hash(empty(), &func.name, func.params.len());
 
                     if lib.contains_key(&hash) {
@@ -2727,7 +2739,9 @@ fn parse_fn(
     lib: &mut FunctionsLib,
     access: FnAccess,
     mut settings: ParseSettings,
-    comments: StaticVec<String>,
+    #[cfg(not(feature = "no_function"))]
+    #[cfg(feature = "metadata")]
+    comments: StaticVec<crate::stdlib::string::String>,
 ) -> Result<ScriptFnDef, ParseError> {
     #[cfg(not(feature = "unchecked"))]
     settings.ensure_level_within_max_limit(state.max_expr_depth)?;
@@ -2814,6 +2828,8 @@ fn parse_fn(
         lib: None,
         #[cfg(not(feature = "no_module"))]
         mods: Default::default(),
+        #[cfg(not(feature = "no_function"))]
+        #[cfg(feature = "metadata")]
         comments,
     })
 }
@@ -2967,6 +2983,8 @@ fn parse_anon_fn(
         lib: None,
         #[cfg(not(feature = "no_module"))]
         mods: Default::default(),
+        #[cfg(not(feature = "no_function"))]
+        #[cfg(feature = "metadata")]
         comments: Default::default(),
     };