diff --git a/spacy/syntax/transition_system.pxd b/spacy/syntax/transition_system.pxd
index 387cd0fc9..4cf9aae7e 100644
--- a/spacy/syntax/transition_system.pxd
+++ b/spacy/syntax/transition_system.pxd
@@ -47,6 +47,6 @@ cdef class TransitionSystem:
     cdef Transition init_transition(self, int clas, int move, int label) except *
 
     cdef int set_valid(self, int* output, StateClass state) nogil
-    
+
     cdef int set_costs(self, int* is_valid, int* costs,
                        StateClass state, GoldParse gold) except -1