diff --git a/Code/TKStateMachine.h b/Code/TKStateMachine.h
index d02168f..06969d4 100644
--- a/Code/TKStateMachine.h
+++ b/Code/TKStateMachine.h
@@ -228,12 +228,12 @@ extern NSString *const TKErrorDomain;
 extern NSString *const TKStateMachineDidChangeStateNotification;
 
 /**
- A key in the `userInfo` dictionary of a `TKStateMachineDidChangeStateNotification` notification specifying the state of the machine before the transition occured.
+ A key in the `userInfo` dictionary of a `TKStateMachineDidChangeStateNotification` notification specifying the state of the machine before the transition occurred.
  */
 extern NSString *const TKStateMachineDidChangeStateOldStateUserInfoKey DEPRECATED_MSG_ATTRIBUTE("Use TKStateMachineDidChangeStateTransitionUserInfoKey instead (transition.sourceState).");
 
 /**
- A key in the `userInfo` dictionary of a `TKStateMachineDidChangeStateNotification` notification specifying the state of the machine after the transition occured.
+ A key in the `userInfo` dictionary of a `TKStateMachineDidChangeStateNotification` notification specifying the state of the machine after the transition occurred.
  */
 extern NSString *const TKStateMachineDidChangeStateNewStateUserInfoKey DEPRECATED_MSG_ATTRIBUTE("Use TKStateMachineDidChangeStateTransitionUserInfoKey instead (transition.destinationState).");
 
diff --git a/Code/TKTransition.h b/Code/TKTransition.h
index 91c5aa6..f683481 100644
--- a/Code/TKTransition.h
+++ b/Code/TKTransition.h
@@ -32,11 +32,11 @@
 ///----------------------------
 
 /**
- Creates and returns a new transition object describing a state change occuring within a state machine in response to the firing of an event.
+ Creates and returns a new transition object describing a state change occurring within a state machine in response to the firing of an event.
 
  @param event The event being fired that is causing the transition to occur.
  @param sourceState The state of the machine when the event was fired.
- @param stateMachine The state machine in which the transition is occurirng.
+ @param stateMachine The state machine in which the transition is occurring.
  @param userInfo An optional dictionary of user info supplied with the event when it was fired.
  */
 + (instancetype)transitionForEvent:(TKEvent *)event fromState:(TKState *)sourceState inStateMachine:(TKStateMachine *)stateMachine userInfo:(NSDictionary *)userInfo;