diff --git a/Source/CesiumRuntime/Private/CesiumGltfComponent.cpp b/Source/CesiumRuntime/Private/CesiumGltfComponent.cpp
index b2781a59a..ae6d3ca00 100644
--- a/Source/CesiumRuntime/Private/CesiumGltfComponent.cpp
+++ b/Source/CesiumRuntime/Private/CesiumGltfComponent.cpp
@@ -1522,9 +1522,7 @@ static void loadPrimitive(
             material.emissiveTexture,
             gltfToUnrealTexCoordMap);
 
-    for (size_t i = 0;
-         i < primitiveResult.overlayTextureCoordinateIDToUVIndex.size();
-         ++i) {
+    for (size_t i = 0; i < 3; ++i) {
       std::string attributeName = "_CESIUMOVERLAY_" + std::to_string(i);
       auto overlayIt = primitive.attributes.find(attributeName);
       if (overlayIt != primitive.attributes.end()) {
@@ -3404,6 +3402,10 @@ void UCesiumGltfComponent::AttachRasterTile(
                   rasterTile.getOverlay().getName(),
                   "_TranslationScale"),
               translationAndScale);
+          check(
+              primData.overlayTextureCoordinateIDToUVIndex.find(
+                  textureCoordinateID) !=
+              primData.overlayTextureCoordinateIDToUVIndex.end());
           pMaterial->SetScalarParameterValue(
               createSafeName(
                   rasterTile.getOverlay().getName(),
diff --git a/Source/CesiumRuntime/Private/CesiumRasterOverlays.h b/Source/CesiumRuntime/Private/CesiumRasterOverlays.h
index 545e24a3d..7c868916a 100644
--- a/Source/CesiumRuntime/Private/CesiumRasterOverlays.h
+++ b/Source/CesiumRuntime/Private/CesiumRasterOverlays.h
@@ -8,5 +8,4 @@ constexpr size_t maximumOverlayTextureCoordinateIDs = 2;
  * @brief Maps an overlay texture coordinate ID to the index of the
  * corresponding texture coordinates in the static mesh's UVs array.
  */
-using OverlayTextureCoordinateIDMap =
-    std::array<int32_t, maximumOverlayTextureCoordinateIDs>;
+using OverlayTextureCoordinateIDMap = std::map<size_t, int32_t>;