diff --git a/macros/src/codegen.rs b/macros/src/codegen.rs
index 158c74f..e109739 100644
--- a/macros/src/codegen.rs
+++ b/macros/src/codegen.rs
@@ -494,6 +494,9 @@ pub fn generate_code(sm: &ParsedStateMachine) -> proc_macro2::TokenStream {
             #guard_list
             #action_list
             #entry_list
+
+            #[allow(missing_docs)]
+            fn transition_callback(&self, new_state: &Option<#states_type_name>) {}
         }
 
         /// List of auto-generated states.
@@ -588,6 +591,7 @@ pub fn generate_code(sm: &ParsedStateMachine) -> proc_macro2::TokenStream {
                         #(#events_type_name::#events => {
                             #code_blocks
 
+                            self.context().transition_callback(&self.state);
                             self.state()
                         }),*
                         _ => {