diff --git a/autotests/read/jxl/gray_linear_lossy.jxl b/autotests/read/jxl/gray_linear_lossy.jxl
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index 0000000..49f6dff
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diff --git a/autotests/read/jxl/gray_linear_lossy.jxl.json b/autotests/read/jxl/gray_linear_lossy.jxl.json
new file mode 100644
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+++ b/autotests/read/jxl/gray_linear_lossy.jxl.json
@@ -0,0 +1,14 @@
+[
+    {
+        "fileName" : "gray_linear_lossy.png",
+        "fuzziness" : 1,
+        "description" : "Minimum fuzziness value to pass the test on all architectures.",
+        "colorSpace" : {
+            "description" : "Gra_D65_Rel_SRG",
+            "primaries" : "Custom",
+            "transferFunction" : "SRgb",
+            "gamma" : 0,
+            "colorModel" : "Gray"
+        }
+    }
+]
diff --git a/autotests/read/jxl/gray_linear_lossy.png b/autotests/read/jxl/gray_linear_lossy.png
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