diff --git a/spacy/tests/util.py b/spacy/tests/util.py
index 359767f1b..29f39ebf6 100644
--- a/spacy/tests/util.py
+++ b/spacy/tests/util.py
@@ -58,7 +58,7 @@ def get_doc(
         for annot in annotations:
             if annot:
                 if annot is heads:
-                    annot = numpy.array(heads).astype(numpy.uint64)
+                    annot = numpy.array(heads, dtype=numpy.int32).astype(numpy.uint64)
                     for i in range(len(words)):
                         if attrs.ndim == 1:
                             attrs[i] = annot[i]
diff --git a/spacy/tokens/span.pyx b/spacy/tokens/span.pyx
index a40347d23..5df8c823b 100644
--- a/spacy/tokens/span.pyx
+++ b/spacy/tokens/span.pyx
@@ -272,7 +272,7 @@ cdef class Span:
                     for ancestor in ancestors:
                         ancestor_i = ancestor.i - self.start
                         if ancestor_i in range(length):
-                            array[i, head_col] = numpy.array(ancestor_i - i).astype(numpy.uint64)
+                            array[i, head_col] = numpy.int32(ancestor_i - i).astype(numpy.uint64)
 
                 # if there is no appropriate ancestor, define a new artificial root
                 value = array[i, head_col]
@@ -280,7 +280,7 @@ cdef class Span:
                     new_root = old_to_new_root.get(ancestor_i, None)
                     if new_root is not None:
                         # take the same artificial root as a previous token from the same sentence
-                        array[i, head_col] = numpy.array(new_root - i).astype(numpy.uint64)
+                        array[i, head_col] = numpy.int32(new_root - i).astype(numpy.uint64)
                     else:
                         # set this token as the new artificial root
                         array[i, head_col] = 0