diff --git a/spacy/syntax/stateclass.pyx b/spacy/syntax/stateclass.pyx
index 6f7951987..81c31be97 100644
--- a/spacy/syntax/stateclass.pyx
+++ b/spacy/syntax/stateclass.pyx
@@ -16,12 +16,11 @@ cdef class StateClass:
         cdef int i
         for i in range(length + (PADDING * 2)):
             self._ents[i].end = -1
+            self._sent[i].l_edge = i
+            self._sent[i].r_edge = i
         for i in range(length, length + (PADDING * 2)):
             self._sent[i].lex = &EMPTY_LEXEME
         self._sent += PADDING
-        for i in range(length):
-            self._sent[i].l_edge = i
-            self._sent[i].r_edge = i
         self._ents += PADDING
         self._buffer += PADDING
         self._stack += PADDING
@@ -162,11 +161,11 @@ cdef class StateClass:
         cdef int dist = h_i - c_i
         cdef TokenC* h = &self._sent[h_i]
         if c_i > h_i:
+            h.r_edge = self.R_(h_i, 2).r_edge if h.r_kids >= 2 else h_i
             h.r_kids -= 1
-            h.r_edge = self.R_(h_i, 2).r_edge if h.r_kids >= 1 else h_i
         else:
+            h.l_edge = self.L_(h_i, 2).l_edge if h.l_kids >= 2 else h_i
             h.l_kids -= 1
-            h.l_edge = self.L_(h_i, 2).l_edge if h.l_kids >= 1 else h_i
 
     cdef void open_ent(self, int label) nogil:
         self._ents[self._e_i].start = self.B(0)
diff --git a/spacy/tokens/doc.pyx b/spacy/tokens/doc.pyx
index 41d24d8ac..ccde5d599 100644
--- a/spacy/tokens/doc.pyx
+++ b/spacy/tokens/doc.pyx
@@ -67,6 +67,8 @@ cdef class Doc:
         cdef int i
         for i in range(size + (PADDING*2)):
             data_start[i].lex = &EMPTY_LEXEME
+            data_start[i].l_edge = i
+            data_start[i].r_edge = i
         self.data = data_start + PADDING
         self.max_length = size
         self.length = 0
@@ -219,6 +221,8 @@ cdef class Doc:
             t.idx = 0
         else:
             t.idx = (t-1).idx + (t-1).lex.length + (t-1).spacy
+        t.l_edge = self.length
+        t.r_edge = self.length
         assert t.lex.orth != 0
         t.spacy = has_space
         self.length += 1
@@ -310,6 +314,8 @@ cdef class Doc:
         self.is_parsed = True
         for i in range(self.length):
             self.data[i] = parsed[i]
+            assert self.data[i].l_edge <= i
+            assert self.data[i].r_edge >= i
 
     def from_array(self, attrs, array):
         cdef int i, col