diff --git a/mellea/formatters/granite/intrinsics/output.py b/mellea/formatters/granite/intrinsics/output.py
index 5eb0bafb34..eac6742445 100644
--- a/mellea/formatters/granite/intrinsics/output.py
+++ b/mellea/formatters/granite/intrinsics/output.py
@@ -724,7 +724,7 @@ def _transform(self, value, path, prepare_output):
                         f"deduplication be present in all rows. "
                         f"Element is: {element}"
                     )
-            key = (element[t] for t in self.target_fields)
+            key = tuple(element[t] for t in self.target_fields)
             key_to_record[key] = element
         return list(key_to_record.values())
 
diff --git a/test/formatters/granite/testdata/test_canned_output/model_output/citations.json b/test/formatters/granite/testdata/test_canned_output/model_output/citations.json
index eb5a18c980..12d862ad9e 100644
--- a/test/formatters/granite/testdata/test_canned_output/model_output/citations.json
+++ b/test/formatters/granite/testdata/test_canned_output/model_output/citations.json
@@ -6,7 +6,7 @@
       "index": 0,
       "logprobs": null,
       "message": {
-        "content": " [{\"r\": 0, \"c\": [8, 11, 13]}, {\"r\": 1, \"c\": []}]",
+        "content": " [{\"r\": 0, \"c\": [8, 8, 11, 13]}, {\"r\": 0, \"c\": [8, 8, 11, 13]}, {\"r\": 1, \"c\": []}]",
         "refusal": null,
         "role": "assistant",
         "annotations": null,