diff --git a/src/lib/style.ts b/src/lib/style.ts
index 68e714a..7741909 100644
--- a/src/lib/style.ts
+++ b/src/lib/style.ts
@@ -118,5 +118,7 @@ function normalizeSource(uri: MapboxURI, accessToken?: string) {
 		result.searchParams.set('access_token', accessToken)
 	}
 
+	result.searchParams.set('secure', '')
+
 	return result.href
 }
diff --git a/test/style.test.ts b/test/style.test.ts
index b4e184b..6eded98 100644
--- a/test/style.test.ts
+++ b/test/style.test.ts
@@ -83,7 +83,7 @@ describe('transformUrls()', () => {
 		expect(streetsV12.sources).toStrictEqual({
 			composite: {
 				type: 'vector',
-				url: 'https://api.mapbox.com/v4/mapbox.mapbox-streets-v8,mapbox.mapbox-terrain-v2,mapbox.mapbox-bathymetry-v2.json',
+				url: 'https://api.mapbox.com/v4/mapbox.mapbox-streets-v8,mapbox.mapbox-terrain-v2,mapbox.mapbox-bathymetry-v2.json?secure=',
 			},
 		})
 	})
@@ -115,7 +115,7 @@ describe('transformUrls()', () => {
 		expect(streetsV12.sources).toStrictEqual({
 			composite: {
 				type: 'vector',
-				url: `https://api.mapbox.com/v4/mapbox.mapbox-streets-v8,mapbox.mapbox-terrain-v2,mapbox.mapbox-bathymetry-v2.json?access_token=${accessToken}`,
+				url: `https://api.mapbox.com/v4/mapbox.mapbox-streets-v8,mapbox.mapbox-terrain-v2,mapbox.mapbox-bathymetry-v2.json?access_token=${accessToken}&secure=`,
 			},
 		})
 	})