diff --git a/collections/N1b_O3.yaml b/collections/N1b_O3.yaml
index 98a16a1d..38583efc 100644
--- a/collections/N1b_O3.yaml
+++ b/collections/N1b_O3.yaml
@@ -20,6 +20,7 @@ Resources:
     Type: Time
     LayerId: composition_europe_o3_analysis_surface
     Styles: [sh_OrangesTransparent240_surface_concentration]
-    OverwriteBBox: [45, 72, -25, 30] # WMS layer description provides incorrect BBox
+    MediaType: image/png
+    OverwriteBBox: [-25, 30, 45, 72] # WMS layer description provides incorrect BBox
 Legend: N1b_O3/cm_legend.png
 Image: N1b_O3/N1b.png