diff --git a/spacy/morphology.pyx b/spacy/morphology.pyx
index fcfe216ba..cc0f61cea 100644
--- a/spacy/morphology.pyx
+++ b/spacy/morphology.pyx
@@ -29,7 +29,8 @@ cdef class Morphology:
     FEATURE_SEP = "|"
     FIELD_SEP = "="
     VALUE_SEP = ","
-    EMPTY_MORPH = "_" # not an empty string so that the PreshMap key is not 0
+    # not an empty string so that the PreshMap key is not 0
+    EMPTY_MORPH = symbols.NAMES[symbols._]
 
     def __init__(self, StringStore strings):
         self.mem = Pool()
diff --git a/spacy/symbols.pxd b/spacy/symbols.pxd
index e516f3ed9..bc15d9b80 100644
--- a/spacy/symbols.pxd
+++ b/spacy/symbols.pxd
@@ -466,3 +466,4 @@ cdef enum symbol_t:
     ENT_ID
 
     IDX
+    _
diff --git a/spacy/symbols.pyx b/spacy/symbols.pyx
index 92607e120..b0345c710 100644
--- a/spacy/symbols.pyx
+++ b/spacy/symbols.pyx
@@ -465,6 +465,7 @@ IDS = {
     "acl": acl,
     "LAW": LAW,
     "MORPH": MORPH,
+    "_": _,
 }