diff --git a/src/datasource/catmaid/frontend.ts b/src/datasource/catmaid/frontend.ts
index 689125023..1ca882dcf 100644
--- a/src/datasource/catmaid/frontend.ts
+++ b/src/datasource/catmaid/frontend.ts
@@ -67,8 +67,6 @@ import type { Borrowed } from "#src/util/disposable.js";
 import { mat4, vec3 } from "#src/util/geom.js";
 import "#src/datasource/catmaid/register_credentials_provider.js";
 
-const METERS_PER_NANOMETER = 1e-9;
-
 export class CatmaidSpatiallyIndexedSkeletonSource
   extends WithParameters(
     WithCredentialsProvider<CatmaidToken>()(SpatiallyIndexedSkeletonSource),
@@ -429,9 +427,9 @@ export class CatmaidDataSourceProvider implements DataSourceProvider {
 
     // The model-space coordinates we emit are in nanometers, converted to meters for Neuroglancer.
     const coordinateScaleFactors = Float64Array.from([
-      METERS_PER_NANOMETER,
-      METERS_PER_NANOMETER,
-      METERS_PER_NANOMETER,
+      1e-9,
+      1e-9,
+      1e-9,
     ]);
 
     // Bounds and chunk sizes are represented in project-space nanometers.
diff --git a/src/datasource/graphene/frontend.ts b/src/datasource/graphene/frontend.ts
index 6b38e5a10..fd18f6d8d 100644
--- a/src/datasource/graphene/frontend.ts
+++ b/src/datasource/graphene/frontend.ts
@@ -1333,7 +1333,7 @@ class GraphConnection extends SegmentationGraphSourceConnection {
     return undefined;
   }
 
-  getMeshSource() {
+  getMeshSource(): MeshSource | undefined {
     const { layer } = this;
     for (const dataSource of layer.dataSources) {
       const { loadState } = dataSource;
@@ -1351,7 +1351,9 @@ class GraphConnection extends SegmentationGraphSourceConnection {
           (subsource) => subsource.id === "mesh",
         )[0];
         if (meshSubsource) {
-          return meshSubsource.subsource.mesh;
+          // `DataSubsource.mesh` is widened for spatial skeleton support, but Graphene
+          // segment updates still target mesh sources.
+          return meshSubsource.subsource.mesh as MeshSource | undefined;
         }
       }
     }
@@ -1359,9 +1361,7 @@ class GraphConnection extends SegmentationGraphSourceConnection {
   }
 
   meshAddNewSegments(segments: bigint[]) {
-    // `DataSubsource.mesh` is widened for spatial skeleton support, but Graphene
-    // segment updates still target mesh sources.
-    const meshSource = this.getMeshSource() as MeshSource | undefined;
+    const meshSource = this.getMeshSource();
     if (meshSource) {
       for (const segment of segments) {
         meshSource.rpc!.invoke(GRAPHENE_MESH_NEW_SEGMENT_RPC_ID, {