diff --git a/spacy/_ml.py b/spacy/_ml.py
index f589704a6..ac7849bbb 100644
--- a/spacy/_ml.py
+++ b/spacy/_ml.py
@@ -19,6 +19,8 @@ import numpy
 
 
 def _init_for_precomputed(W, ops):
+    if (W**2).sum() != 0.:
+        return
     reshaped = W.reshape((W.shape[1], W.shape[0] * W.shape[2]))
     ops.xavier_uniform_init(reshaped)
     W[:] = reshaped.reshape(W.shape)
@@ -247,6 +249,7 @@ def doc2feats(cols=None):
     model.cols = cols
     return model
 
+
 def print_shape(prefix):
     def forward(X, drop=0.):
         return X, lambda dX, **kwargs: dX