diff --git a/src/routes/en/docs/gfs-api/+page.svelte b/src/routes/en/docs/gfs-api/+page.svelte
index 030a651..8a933c8 100644
--- a/src/routes/en/docs/gfs-api/+page.svelte
+++ b/src/routes/en/docs/gfs-api/+page.svelte
@@ -214,6 +214,7 @@
 			{ name: 'convective_inhibition', label: 'Convective Inhibition' },
 			{ name: 'freezing_level_height', label: 'Freezing Level Height' },
 			{ name: 'boundary_layer_height', label: 'Boundary Layer Height PBL' },
+			{ name: 'mass_density_8m', label: 'Mass Density (8 m)' },
 		]
 	];