diff --git a/codegen/src/clone.rs b/codegen/src/clone.rs
index 0dbb67b34..92dbc9669 100644
--- a/codegen/src/clone.rs
+++ b/codegen/src/clone.rs
@@ -1,4 +1,4 @@
-use crate::{cfg, file, lookup};
+use crate::{cfg, file, full, lookup};
 use anyhow::Result;
 use proc_macro2::{Ident, Span, TokenStream};
 use quote::{format_ident, quote};
@@ -13,6 +13,7 @@ fn expand_impl_body(defs: &Definitions, node: &Node) -> TokenStream {
     match &node.data {
         Data::Enum(variants) if variants.is_empty() => quote!(match *self {}),
         Data::Enum(variants) => {
+            let mixed_derive_full = full::is_mixed_derive_full_enum(defs, node);
             let arms = variants.iter().map(|(variant_name, fields)| {
                 let variant = Ident::new(variant_name, Span::call_site());
                 if fields.is_empty() {
@@ -28,9 +29,10 @@ fn expand_impl_body(defs: &Definitions, node: &Node) -> TokenStream {
                         pats.push(pat);
                     }
                     let mut cfg = None;
-                    if node.ident == "Expr" {
+                    if mixed_derive_full {
                         if let Type::Syn(ty) = &fields[0] {
-                            if !lookup::node(defs, ty).features.any.contains("derive") {
+                            let features = &lookup::node(defs, ty).features;
+                            if features.any.contains("full") && !features.any.contains("derive") {
                                 cfg = Some(quote!(#[cfg(feature = "full")]));
                             }
                         }
@@ -41,7 +43,7 @@ fn expand_impl_body(defs: &Definitions, node: &Node) -> TokenStream {
                     }
                 }
             });
-            let nonexhaustive = if node.ident == "Expr" {
+            let nonexhaustive = if mixed_derive_full {
                 Some(quote! {
                     #[cfg(not(feature = "full"))]
                     _ => unreachable!(),
diff --git a/codegen/src/debug.rs b/codegen/src/debug.rs
index ba8353b73..18c5be4c5 100644
--- a/codegen/src/debug.rs
+++ b/codegen/src/debug.rs
@@ -1,5 +1,5 @@
 use crate::cfg::{self, DocCfg};
-use crate::{file, lookup};
+use crate::{file, full, lookup};
 use anyhow::Result;
 use proc_macro2::{Ident, Span, TokenStream};
 use quote::{format_ident, quote};
@@ -54,6 +54,7 @@ fn expand_impl_body(
         Data::Enum(variants) if variants.is_empty() => quote!(match *self {}),
         Data::Enum(variants) => {
             assert!(!is_syntax_tree_variant);
+            let mixed_derive_full = full::is_mixed_derive_full_enum(defs, node);
             let arms = variants.iter().map(|(variant_name, fields)| {
                 let variant = Ident::new(variant_name, Span::call_site());
                 if fields.is_empty() {
@@ -62,9 +63,10 @@ fn expand_impl_body(
                     }
                 } else {
                     let mut cfg = None;
-                    if node.ident == "Expr" {
+                    if mixed_derive_full {
                         if let Type::Syn(ty) = &fields[0] {
-                            if !lookup::node(defs, ty).features.any.contains("derive") {
+                            let features = &lookup::node(defs, ty).features;
+                            if features.any.contains("full") && !features.any.contains("derive") {
                                 cfg = Some(quote!(#[cfg(feature = "full")]));
                             }
                         }
@@ -89,7 +91,7 @@ fn expand_impl_body(
                     }
                 }
             });
-            let nonexhaustive = if node.ident == "Expr" {
+            let nonexhaustive = if mixed_derive_full {
                 Some(quote! {
                     #[cfg(not(feature = "full"))]
                     _ => unreachable!(),
diff --git a/codegen/src/eq.rs b/codegen/src/eq.rs
index cf08a9540..8effffd4c 100644
--- a/codegen/src/eq.rs
+++ b/codegen/src/eq.rs
@@ -1,4 +1,4 @@
-use crate::{cfg, file, lookup};
+use crate::{cfg, file, full, lookup};
 use anyhow::Result;
 use proc_macro2::{Ident, Span, TokenStream};
 use quote::{format_ident, quote};
@@ -23,6 +23,7 @@ fn expand_impl_body(defs: &Definitions, node: &Node) -> TokenStream {
     match &node.data {
         Data::Enum(variants) if variants.is_empty() => quote!(match *self {}),
         Data::Enum(variants) => {
+            let mixed_derive_full = full::is_mixed_derive_full_enum(defs, node);
             let arms = variants.iter().map(|(variant_name, fields)| {
                 let variant = Ident::new(variant_name, Span::call_site());
                 if fields.is_empty() {
@@ -57,9 +58,10 @@ fn expand_impl_body(defs: &Definitions, node: &Node) -> TokenStream {
                         comparisons.push(quote!(true));
                     }
                     let mut cfg = None;
-                    if node.ident == "Expr" {
+                    if mixed_derive_full {
                         if let Type::Syn(ty) = &fields[0] {
-                            if !lookup::node(defs, ty).features.any.contains("derive") {
+                            let features = &lookup::node(defs, ty).features;
+                            if features.any.contains("full") && !features.any.contains("derive") {
                                 cfg = Some(quote!(#[cfg(feature = "full")]));
                             }
                         }
diff --git a/codegen/src/full.rs b/codegen/src/full.rs
index a41003189..eeeadd1e9 100644
--- a/codegen/src/full.rs
+++ b/codegen/src/full.rs
@@ -1,5 +1,7 @@
+use crate::lookup;
 use proc_macro2::TokenStream;
 use quote::quote;
+use syn_codegen::{Data, Definitions, Node, Type};
 
 pub fn get_macro() -> TokenStream {
     quote! {
@@ -18,3 +20,71 @@ pub fn get_macro() -> TokenStream {
         }
     }
 }
+
+/// Syntax tree enum that has some variants enabled in "derive" mode and the
+/// rest enabled in "full" mode.
+pub fn is_mixed_derive_full_enum(defs: &Definitions, node: &Node) -> bool {
+    if !(node.features.any.contains("derive") && node.features.any.contains("full")) {
+        return false;
+    }
+
+    let variants = match &node.data {
+        Data::Enum(variants) => variants,
+        Data::Private | Data::Struct(_) => return false,
+    };
+
+    let mut has_derive = false;
+    let mut has_full = false;
+    for fields in variants.values() {
+        match classify_variant(defs, fields) {
+            VariantAvailability::Derive => has_derive = true,
+            VariantAvailability::Full => has_full = true,
+            VariantAvailability::Other => {}
+        }
+    }
+    has_derive && has_full
+}
+
+enum VariantAvailability {
+    Derive,
+    Full,
+    Other,
+}
+
+fn classify_variant(defs: &Definitions, fields: &[Type]) -> VariantAvailability {
+    let mut has_derive = false;
+    let mut has_full = false;
+    for field in fields {
+        for_each_syn_type(field, &mut |ty| {
+            let node = lookup::node(defs, ty);
+            let derive = node.features.any.contains("derive");
+            let full = node.features.any.contains("full");
+            match (derive, full) {
+                (false, false) => {}
+                (false, true) => has_full = true,
+                (true, false | true) => has_derive = true,
+            }
+        });
+    }
+    if has_full {
+        VariantAvailability::Full
+    } else if has_derive {
+        VariantAvailability::Derive
+    } else {
+        VariantAvailability::Other
+    }
+}
+
+fn for_each_syn_type(ty: &Type, f: &mut dyn FnMut(&str)) {
+    match ty {
+        Type::Syn(ty) => f(ty),
+        Type::Std(_) | Type::Ext(_) | Type::Token(_) | Type::Group(_) => {}
+        Type::Punctuated(punctuated) => for_each_syn_type(&punctuated.element, f),
+        Type::Option(ty) | Type::Box(ty) | Type::Vec(ty) => for_each_syn_type(ty, f),
+        Type::Tuple(elements) => {
+            for ty in elements {
+                for_each_syn_type(ty, f);
+            }
+        }
+    }
+}
diff --git a/codegen/src/hash.rs b/codegen/src/hash.rs
index fda5da278..2416d94e8 100644
--- a/codegen/src/hash.rs
+++ b/codegen/src/hash.rs
@@ -1,4 +1,4 @@
-use crate::{cfg, file, lookup};
+use crate::{cfg, file, full, lookup};
 use anyhow::Result;
 use proc_macro2::{Ident, Span, TokenStream};
 use quote::{format_ident, quote};
@@ -23,6 +23,7 @@ fn expand_impl_body(defs: &Definitions, node: &Node) -> TokenStream {
     match &node.data {
         Data::Enum(variants) if variants.is_empty() => quote!(match *self {}),
         Data::Enum(variants) => {
+            let mixed_derive_full = full::is_mixed_derive_full_enum(defs, node);
             let arms = variants
                 .iter()
                 .enumerate()
@@ -60,9 +61,11 @@ fn expand_impl_body(defs: &Definitions, node: &Node) -> TokenStream {
                             pats.push(var);
                         }
                         let mut cfg = None;
-                        if node.ident == "Expr" {
+                        if mixed_derive_full {
                             if let Type::Syn(ty) = &fields[0] {
-                                if !lookup::node(defs, ty).features.any.contains("derive") {
+                                let features = &lookup::node(defs, ty).features;
+                                if features.any.contains("full") && !features.any.contains("derive")
+                                {
                                     cfg = Some(quote!(#[cfg(feature = "full")]));
                                 }
                             }
@@ -76,7 +79,7 @@ fn expand_impl_body(defs: &Definitions, node: &Node) -> TokenStream {
                         }
                     }
                 });
-            let nonexhaustive = if node.ident == "Expr" {
+            let nonexhaustive = if mixed_derive_full {
                 Some(quote! {
                     #[cfg(not(feature = "full"))]
                     _ => unreachable!(),