diff --git a/spacy/syntax/nn_parser.pyx b/spacy/syntax/nn_parser.pyx
index 3e5566705..7412ebeee 100644
--- a/spacy/syntax/nn_parser.pyx
+++ b/spacy/syntax/nn_parser.pyx
@@ -524,6 +524,7 @@ cdef class Parser:
             scores, bp_scores = vec2scores.begin_update(vector, drop=drop)
 
             d_scores = self.get_batch_loss(states, golds, scores)
+            d_scores /= len(docs)
             d_vector = bp_scores(d_scores, sgd=sgd)
             if drop != 0:
                 d_vector *= mask
@@ -582,7 +583,9 @@ cdef class Parser:
                                         width, density,
                                         sgd=sgd, drop=drop, losses=losses)
         backprop_lower = []
+        cdef float batch_size = len(docs)
         for i, d_scores in enumerate(states_d_scores):
+            d_scores /= batch_size
             if losses is not None:
                 losses[self.name] += (d_scores**2).sum()
             ids, bp_vectors, bp_scores = backprops[i]