diff --git a/spacy/tests/doc/test_doc_api.py b/spacy/tests/doc/test_doc_api.py
index c6195d7e2ac..10700b7874a 100644
--- a/spacy/tests/doc/test_doc_api.py
+++ b/spacy/tests/doc/test_doc_api.py
@@ -567,6 +567,7 @@ def test_doc_api_from_docs(en_tokenizer, de_tokenizer):
         "Merging the docs is fun.",
         "",
         "They don't think alike. ",
+        "",
         "Another doc.",
     ]
     en_texts_without_empty = [t for t in en_texts if len(t)]
@@ -574,9 +575,9 @@ def test_doc_api_from_docs(en_tokenizer, de_tokenizer):
     en_docs = [en_tokenizer(text) for text in en_texts]
     en_docs[0].spans["group"] = [en_docs[0][1:4]]
     en_docs[2].spans["group"] = [en_docs[2][1:4]]
-    en_docs[3].spans["group"] = [en_docs[3][0:1]]
+    en_docs[4].spans["group"] = [en_docs[4][0:1]]
     span_group_texts = sorted(
-        [en_docs[0][1:4].text, en_docs[2][1:4].text, en_docs[3][0:1].text]
+        [en_docs[0][1:4].text, en_docs[2][1:4].text, en_docs[4][0:1].text]
     )
     de_doc = de_tokenizer(de_text)
     Token.set_extension("is_ambiguous", default=False)
diff --git a/spacy/tokens/doc.pyx b/spacy/tokens/doc.pyx
index 362a1778455..2f82a0d1bdf 100644
--- a/spacy/tokens/doc.pyx
+++ b/spacy/tokens/doc.pyx
@@ -1183,7 +1183,7 @@ cdef class Doc:
                 token_offset = -1
                 for doc in docs[:-1]:
                     token_offset += len(doc)
-                    if not (len(doc) > 0 and doc[-1].is_space):
+                    if len(doc) > 0 and not doc[-1].is_space:
                         concat_spaces[token_offset] = True
 
         concat_array = numpy.concatenate(arrays)