diff --git a/src/ast.rs b/src/ast.rs
index 0a69dd17..910352fe 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -7,9 +7,9 @@ use crate::stdlib::{
     borrow::Cow,
     boxed::Box,
     fmt,
-    hash::{Hash, Hasher},
+    hash::Hash,
     num::{NonZeroU64, NonZeroUsize},
-    ops::{Add, AddAssign, Deref, DerefMut},
+    ops::{Add, AddAssign},
     string::String,
     vec,
     vec::Vec,
@@ -1131,7 +1131,7 @@ pub struct FloatWrapper(FLOAT);
 
 #[cfg(not(feature = "no_float"))]
 impl Hash for FloatWrapper {
-    fn hash<H: Hasher>(&self, state: &mut H) {
+    fn hash<H: crate::stdlib::hash::Hasher>(&self, state: &mut H) {
         self.0.to_le_bytes().hash(state);
     }
 }
@@ -1151,7 +1151,7 @@ impl AsMut<FLOAT> for FloatWrapper {
 }
 
 #[cfg(not(feature = "no_float"))]
-impl Deref for FloatWrapper {
+impl crate::stdlib::ops::Deref for FloatWrapper {
     type Target = FLOAT;
 
     fn deref(&self) -> &Self::Target {
@@ -1160,7 +1160,7 @@ impl Deref for FloatWrapper {
 }
 
 #[cfg(not(feature = "no_float"))]
-impl DerefMut for FloatWrapper {
+impl crate::stdlib::ops::DerefMut for FloatWrapper {
     fn deref_mut(&mut self) -> &mut Self::Target {
         &mut self.0
     }
diff --git a/src/module/mod.rs b/src/module/mod.rs
index c145e217..64788b74 100644
--- a/src/module/mod.rs
+++ b/src/module/mod.rs
@@ -1676,9 +1676,8 @@ impl Module {
     }
 
     /// Get an iterator to the functions in the [`Module`].
-    #[cfg(not(feature = "no_optimize"))]
-    #[cfg(not(feature = "no_function"))]
     #[inline(always)]
+    #[allow(dead_code)]
     pub(crate) fn iter_fn(&self) -> impl Iterator<Item = &FuncInfo> {
         self.functions.values()
     }
diff --git a/src/serde_impl/metadata.rs b/src/serde_impl/metadata.rs
index 85a63d87..94fc32c6 100644
--- a/src/serde_impl/metadata.rs
+++ b/src/serde_impl/metadata.rs
@@ -145,7 +145,14 @@ impl From<&crate::module::FuncInfo> for FnMetadata {
                 .or_else(|| Some("()".to_string())),
             signature: info.gen_signature(),
             doc_comments: if info.func.is_script() {
-                info.func.get_fn_def().comments.clone()
+                #[cfg(feature = "no_function")]
+                {
+                    unreachable!()
+                }
+                #[cfg(not(feature = "no_function"))]
+                {
+                    info.func.get_fn_def().comments.clone()
+                }
             } else {
                 Default::default()
             },
@@ -212,7 +219,7 @@ impl Engine {
     /// 4) Functions in global modules (optional)
     pub fn gen_fn_metadata_with_ast_to_json(
         &self,
-        ast: &AST,
+        _ast: &AST,
         include_global: bool,
     ) -> serde_json::Result<String> {
         let mut global: ModuleMetadata = Default::default();
@@ -233,7 +240,8 @@ impl Engine {
             .map(|f| f.into())
             .for_each(|info| global.functions.push(info));
 
-        ast.iter_functions()
+        #[cfg(not(feature = "no_function"))]
+        _ast.iter_functions()
             .map(|f| f.into())
             .for_each(|info| global.functions.push(info));