diff --git a/spacy/pipeline/span_finder.py b/spacy/pipeline/span_finder.py
index f06ea731a..bdfa055f3 100644
--- a/spacy/pipeline/span_finder.py
+++ b/spacy/pipeline/span_finder.py
@@ -229,21 +229,23 @@ class SpanFinder(TrainablePipe):
         offset = 0
         for i, doc in enumerate(docs):
             doc.spans[self.predicted_key] = []
-            doc_scores = scores[offset : offset + len(doc)]
-            for j in range(len(doc)):
-                start_token_score = doc_scores[j]
-                # If token is a START then start scanning following tokens
-                if start_token_score[0] >= self.threshold:
-                    for k in range(j, len(doc)):
-                        end_token_score = doc_scores[k]
-                        # If token is an END check whether the lenght contraint is met
-                        if end_token_score[1] >= self.threshold:
-                            span_length = k + 1 - j
-                            if span_length > self.max_length:
-                                break
-                            elif self.min_length <= span_length:
-                                span = doc[j : k + 1]
-                                doc.spans[self.predicted_key].append(span)
+            starts = []
+            ends = []
+            doc_scores = scores[offset:offset + len(doc)]
+
+            for token, token_score in zip(doc, doc_scores):
+                if token_score[0] >= self.threshold:
+                    starts.append(token.i)
+                if token_score[1] >= self.threshold:
+                    ends.append(token.i)
+
+            for start in starts:
+                for end in ends:
+                    span_length = end + 1 - start
+                    if span_length > self.max_length:
+                        break
+                    elif self.min_length <= span_length:
+                        doc.spans[self.predicted_key].append(doc[start : end + 1])
 
     def update(
         self,