diff --git a/test/examples_assertions/duplicated_field.yaml b/test/examples_assertions/duplicated_field.yaml
index 1bde6da..ce97222 100644
--- a/test/examples_assertions/duplicated_field.yaml
+++ b/test/examples_assertions/duplicated_field.yaml
@@ -37,9 +37,9 @@ objective:
             name: Reaction
             field: y
   references:
-    'ref_x.reac':
+    'ref_x.txt':
       prediction: ['reaction_x', 'reaction_x_1']
       filter_tol: 1e-6
-    'ref_y.reac':
+    'ref_y.txt':
       prediction: ['reaction_y', 'reaction_y_1']
       filter_tol: 1e-6
diff --git a/test/examples_assertions/ref_x.txt b/test/examples_assertions/ref_x.txt
new file mode 100644
index 0000000..2d032a0
--- /dev/null
+++ b/test/examples_assertions/ref_x.txt
@@ -0,0 +1,101 @@
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diff --git a/test/examples_assertions/ref_y.txt b/test/examples_assertions/ref_y.txt
new file mode 100644
index 0000000..88b88ff
--- /dev/null
+++ b/test/examples_assertions/ref_y.txt
@@ -0,0 +1,101 @@
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