diff --git a/bindgen/callbacks.rs b/bindgen/callbacks.rs
index d58c502255..2fb58e7b04 100644
--- a/bindgen/callbacks.rs
+++ b/bindgen/callbacks.rs
@@ -1,7 +1,7 @@
 //! A public API for more fine-grained customization of bindgen behavior.
 
 pub use crate::ir::analysis::DeriveTrait;
-pub use crate::ir::comp::MethodKind as AttributeMethodKind;
+pub use crate::ir::function::FunctionKind;
 pub use crate::ir::derive::CanDerive as ImplementsTrait;
 pub use crate::ir::enum_ty::{EnumVariantCustomBehavior, EnumVariantValue};
 pub use crate::ir::int::IntKind;
@@ -242,7 +242,7 @@ pub struct AttributeInfo<'a> {
     /// The kind of the item.
     pub kind: AttributeItemKind,
     /// The kind of a method item.
-    pub method_kind: Option<AttributeMethodKind>,
+    pub fn_kind: Option<FunctionKind>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
diff --git a/bindgen/codegen/mod.rs b/bindgen/codegen/mod.rs
index bcf701818a..890b249609 100644
--- a/bindgen/codegen/mod.rs
+++ b/bindgen/codegen/mod.rs
@@ -1071,7 +1071,7 @@ impl CodeGenerator for Type {
                                 cb.add_attributes(&AttributeInfo {
                                     name: &name,
                                     kind: AttributeItemKind::Struct,
-                                    method_kind: None,
+                                    fn_kind: None,
                                 })
                             });
                         attributes.extend(
@@ -2538,7 +2538,7 @@ impl CodeGenerator for CompInfo {
                 } else {
                     AttributeItemKind::Struct
                 },
-                method_kind: None,
+                fn_kind: None,
             })
         });
         attributes.extend(custom_attributes.iter().map(|s| s.parse().unwrap()));
@@ -3154,7 +3154,7 @@ impl Method {
             cb.add_attributes(&AttributeInfo {
                 name: &canonical_name,
                 kind: AttributeItemKind::Function,
-                method_kind: Some(self.kind()),
+                fn_kind: Some(FunctionKind::Method(self.kind())),
             })
         });
         attrs.extend(custom_attributes.iter().map(|s| s.parse().unwrap()));
@@ -3740,7 +3740,7 @@ impl CodeGenerator for Enum {
                 cb.add_attributes(&AttributeInfo {
                     name: &name,
                     kind: AttributeItemKind::Enum,
-                    method_kind: None,
+                    fn_kind: None,
                 })
             });
             attrs.extend(custom_attributes.iter().map(|s| s.parse().unwrap()));
@@ -4605,6 +4605,15 @@ impl CodeGenerator for Function {
 
         let mut attributes = vec![];
 
+        let custom_attributes = ctx.options().all_callbacks(|cb| {
+            cb.add_attributes(&AttributeInfo {
+                name: &canonical_name,
+                kind: AttributeItemKind::Function,
+                fn_kind: Some(self.kind()),
+            })
+        });
+        attributes.extend(custom_attributes.iter().map(|s| s.parse().unwrap()));
+
         if true {
             let must_use = signature.must_use() || {
                 let ret_ty = signature
diff --git a/bindgen/ir/function.rs b/bindgen/ir/function.rs
index 2474ea839a..6f59ae2ea7 100644
--- a/bindgen/ir/function.rs
+++ b/bindgen/ir/function.rs
@@ -19,7 +19,7 @@ const RUST_DERIVE_FUNPTR_LIMIT: usize = 12;
 
 /// What kind of function are we looking at?
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
-pub(crate) enum FunctionKind {
+pub enum FunctionKind {
     /// A plain, free function.
     Function,
     /// A method of some kind.