diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 54a12290672275acc18d81f0d30c2768e601a609..df4344db5fa7e885b95cc6f7a506f169b5826362 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -49,28 +49,26 @@ pages:
     paths:
       - public
 
-
 build_develop:
   except:
     - master
   stage: build_develop
-  image: docker:18.09.7
+  image: docker:23.0.3
   services:
-    - 'docker:18.09.7-dind'
+    - "docker:23.0.3-dind"
   script:
     - docker build -t $CI_REGISTRY_IMAGE:develop .
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
     - docker push $CI_REGISTRY_IMAGE:develop
 
-
 build_master:
   stage: build_master
-  image: 'docker:18.09.7'
+  image: "docker:23.0.3"
   only:
     - master
   services:
-    - 'docker:18.09.7-dind'
+    - "docker:23.0.3-dind"
   script:
     - docker build -t $CI_REGISTRY_IMAGE:latest .
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
-    - docker push $CI_REGISTRY_IMAGE:latest
\ No newline at end of file
+    - docker push $CI_REGISTRY_IMAGE:latest
diff --git a/src/utils.py b/src/utils.py
index 9d0c06d8e37be0d8952582c7bec251982d5ce150..b005d8d3abc4333210eb0630cab0cdb5f3ed6a2c 100644
--- a/src/utils.py
+++ b/src/utils.py
@@ -837,7 +837,7 @@ def get_pos_sentences(document, marker_start, marker_stop, pos_list):
     for idx, token in enumerate(tokens):
         if token.lexemes[0].pos.split(":")[0] in pos_to_mark:
             start, stop = token.start, token.stop
-            choosen_tokens.append(document.text[start:stop])
+            choosen_tokens.append(token.id)
             part_start = tokens[
                 max(idx - LINKING_MARGIN_SIZE, 0)
             ].start