diff --git a/src/index.ts b/src/index.ts
index c7c15ee..abb868f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -19,3 +19,7 @@ export {
     ActivityProfileLayer,
     ActivityProfileLayerProps,
 } from "./layers/activity-profile-layer/activity-profile-layer";
+export {
+    ActivityLayer,
+    ActivityLayerProps,
+} from "./layers/activity-layer/activity-layer";
diff --git a/src/layers/face-profile-layer/util/extrudeRoadMeshes.ts b/src/layers/face-profile-layer/util/extrudeRoadMeshes.ts
index 89598d8..6fdc780 100644
--- a/src/layers/face-profile-layer/util/extrudeRoadMeshes.ts
+++ b/src/layers/face-profile-layer/util/extrudeRoadMeshes.ts
@@ -114,7 +114,7 @@ export function extrudeRoadMeshes(
                 segmentTangents[i - 1][1],
             ];
             const [dx2, dy2] = [segmentTangents[i][0], segmentTangents[i][1]];
-            const perp1 = [-dy1, dx1];
+            const perp1: [number, number] = [-dy1, dx1];
             const perp2 = [-dy2, dx2];
             const mx = perp1[0] + perp2[0];
             const my = perp1[1] + perp2[1];