diff --git a/spacy/training/initialize.py b/spacy/training/initialize.py
index e90617852..9cf759c55 100644
--- a/spacy/training/initialize.py
+++ b/spacy/training/initialize.py
@@ -133,10 +133,11 @@ def init_vocab(
         logger.info("Added vectors: %s", vectors)
     # warn if source model vectors are not identical
     sourced_vectors_hashes = nlp.meta.pop("_sourced_vectors_hashes", {})
-    vectors_hash = hash(nlp.vocab.vectors.to_bytes(exclude=["strings"]))
-    for sourced_component, sourced_vectors_hash in sourced_vectors_hashes.items():
-        if vectors_hash != sourced_vectors_hash:
-            warnings.warn(Warnings.W113.format(name=sourced_component))
+    if len(sourced_vectors_hashes) > 0:
+        vectors_hash = hash(nlp.vocab.vectors.to_bytes(exclude=["strings"]))
+        for sourced_component, sourced_vectors_hash in sourced_vectors_hashes.items():
+            if vectors_hash != sourced_vectors_hash:
+                warnings.warn(Warnings.W113.format(name=sourced_component))
     logger.info("Finished initializing nlp object")