diff --git a/crates/lang/codegen/src/generator/dispatch.rs b/crates/lang/codegen/src/generator/dispatch.rs
index acfcc174ea..fee922033e 100644
--- a/crates/lang/codegen/src/generator/dispatch.rs
+++ b/crates/lang/codegen/src/generator/dispatch.rs
@@ -154,48 +154,37 @@ impl Dispatch<'_> {
     ) -> TokenStream2 {
         let span = self.contract.module().storage().span();
         let storage_ident = self.contract.module().storage().ident();
-        let inherent_ids = self
+        let message_ids = self
             .contract
             .module()
             .impls()
-            .filter(|item_impl| item_impl.trait_path().is_none())
-            .flat_map(|item_impl| item_impl.iter_messages())
-            .map(|message| {
-                let span = message.span();
-                message_spans.push(span);
-                let id = message
-                    .composed_selector()
-                    .into_be_u32()
-                    .hex_padded_suffixed();
-                quote_spanned!(span=> #id)
+            .flat_map(|item_impl| {
+                iter::repeat(item_impl.trait_path()).zip(item_impl.iter_messages())
             })
-            .collect::<Vec<_>>();
-        let trait_ids = self
-            .contract
-            .module()
-            .impls()
-            .filter_map(|item_impl| {
-                item_impl
-                    .trait_path()
-                    .map(|trait_path| {
-                        iter::repeat(trait_path).zip(item_impl.iter_messages())
-                    })
-            })
-            .flatten()
             .map(|(trait_path, message)| {
-                let local_id = message.local_id().hex_padded_suffixed();
                 let span = message.span();
                 message_spans.push(span);
-                quote_spanned!(span=>
-                    {
-                        ::core::primitive::u32::from_be_bytes(
-                            <<::ink_lang::reflect::TraitDefinitionRegistry<<#storage_ident as ::ink_lang::reflect::ContractEnv>::Env>
-                                as #trait_path>::__ink_TraitInfo
-                                as ::ink_lang::reflect::TraitMessageInfo<#local_id>>::SELECTOR
-                        )
-                    }
-                )
-            });
+
+                if let Some(trait_path) = trait_path {
+                    let local_id = message.local_id().hex_padded_suffixed();
+                    quote_spanned!(span=>
+                        {
+                            ::core::primitive::u32::from_be_bytes(
+                                <<::ink_lang::reflect::TraitDefinitionRegistry<<#storage_ident as ::ink_lang::reflect::ContractEnv>::Env>
+                                    as #trait_path>::__ink_TraitInfo
+                                    as ::ink_lang::reflect::TraitMessageInfo<#local_id>>::SELECTOR
+                            )
+                        }
+                    )
+                } else {
+                    let id = message
+                        .composed_selector()
+                        .into_be_u32()
+                        .hex_padded_suffixed();
+                    quote_spanned!(span=> #id)
+                }
+            })
+            .collect::<Vec<_>>();
         quote_spanned!(span=>
             impl ::ink_lang::reflect::ContractDispatchableMessages<{
                 <#storage_ident as ::ink_lang::reflect::ContractAmountDispatchables>::MESSAGES
@@ -204,8 +193,7 @@ impl Dispatch<'_> {
                     ::core::primitive::u32;
                     <#storage_ident as ::ink_lang::reflect::ContractAmountDispatchables>::MESSAGES
                 ] = [
-                    #( #inherent_ids , )*
-                    #( #trait_ids ),*
+                    #( #message_ids , )*
                 ];
             }
         )
diff --git a/crates/lang/tests/ui/contract/pass/message-selector.rs b/crates/lang/tests/ui/contract/pass/message-selector.rs
index 303c699076..9f883d6f6d 100644
--- a/crates/lang/tests/ui/contract/pass/message-selector.rs
+++ b/crates/lang/tests/ui/contract/pass/message-selector.rs
@@ -6,20 +6,45 @@ mod contract {
     #[ink(storage)]
     pub struct Contract {}
 
+    #[ink_lang::trait_definition]
+    pub trait Messages {
+        #[ink(message)]
+        fn message_0(&self);
+
+        #[ink(message, selector = 1)]
+        fn message_1(&self);
+    }
+
+    impl Messages for Contract {
+        #[ink(message)]
+        fn message_0(&self) {}
+
+        #[ink(message, selector = 1)]
+        fn message_1(&self) {}
+    }
+
     impl Contract {
         #[ink(constructor)]
         pub fn constructor() -> Self {
             Self {}
         }
 
-        #[ink(message)]
-        pub fn message_0(&self) {}
-
-        #[ink(message, selector = 1)]
-        pub fn message_1(&self) {}
-
         #[ink(message, selector = 0xC0DE_CAFE)]
         pub fn message_2(&self) {}
+
+        #[ink(message, selector = _)]
+        pub fn message_3(&self) {}
+    }
+
+    #[ink_lang::trait_definition]
+    pub trait Messages2 {
+        #[ink(message, selector = 0x12345678)]
+        fn message_4(&self);
+    }
+
+    impl Messages2 for Contract {
+        #[ink(message, selector = 0x12345678)]
+        fn message_4(&self) {}
     }
 }
 
@@ -34,7 +59,7 @@ fn main() {
                 >>::IDS[0]
             },
         >>::SELECTOR,
-        [0x5A, 0x6A, 0xC1, 0x5D],
+        [0xFB, 0xAB, 0x03, 0xCE],
     );
     assert_eq!(
         <Contract as ::ink_lang::reflect::DispatchableMessageInfo<
@@ -60,4 +85,28 @@ fn main() {
         >>::SELECTOR,
         0xC0DE_CAFE_u32.to_be_bytes(),
     );
+    assert_eq!(
+        <Contract as ::ink_lang::reflect::DispatchableMessageInfo<
+            {
+                <Contract as ::ink_lang::reflect::ContractDispatchableMessages<
+                    {
+                        <Contract as ::ink_lang::reflect::ContractAmountDispatchables>::MESSAGES
+                    },
+                >>::IDS[3]
+            },
+        >>::SELECTOR,
+        [0xB6, 0xC3, 0x27, 0x49],
+    );
+    assert_eq!(
+        <Contract as ::ink_lang::reflect::DispatchableMessageInfo<
+            {
+                <Contract as ::ink_lang::reflect::ContractDispatchableMessages<
+                    {
+                        <Contract as ::ink_lang::reflect::ContractAmountDispatchables>::MESSAGES
+                    },
+                >>::IDS[4]
+            },
+        >>::SELECTOR,
+        0x12345678_u32.to_be_bytes(),
+    );
 }