diff --git a/package-lock.json b/package-lock.json
index 0720126..da35cd1 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1227,9 +1227,9 @@
       }
     },
     "@kitware/vtk.js": {
-      "version": "17.7.0",
-      "resolved": "https://registry.npmjs.org/@kitware/vtk.js/-/vtk.js-17.7.0.tgz",
-      "integrity": "sha512-9gBnfQSN+ACUYxnMRHqaL+rffIr3FIrZ9v7xuLln3T3fEdKAddgX/51hnvoRpa1zZF+WUGSNctKN+HprZHlbWQ==",
+      "version": "17.7.2",
+      "resolved": "https://registry.npmjs.org/@kitware/vtk.js/-/vtk.js-17.7.2.tgz",
+      "integrity": "sha512-hYL1LjPo12XGmu/Ir8M87AqydEt894I3KWC3WdlUROcAeX2Ttc59EsI33XikVE5s7p7Qc+IvMxPC8lE7FtAXuw==",
       "requires": {
         "@babel/runtime": "7.12.5",
         "blueimp-md5": "2.18.0",
diff --git a/package.json b/package.json
index 950f942..e95e840 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
   "source": "src/index.js",
   "dependencies": {
     "@babel/runtime": "^7.12.5",
-    "@kitware/vtk.js": "17.7.0"
+    "@kitware/vtk.js": "17.7.2"
   },
   "scripts": {
     "prebuild": "npm run fix",
diff --git a/src/AvailableClasses.js b/src/AvailableClasses.js
index 2e05349..0eb12b7 100644
--- a/src/AvailableClasses.js
+++ b/src/AvailableClasses.js
@@ -20,6 +20,8 @@ import '@kitware/vtk.js/IO/Geometry/PLYReader.js';
 import '@kitware/vtk.js/IO/Geometry/STLReader.js';
 import '@kitware/vtk.js/IO/Misc/ElevationReader.js';
 import '@kitware/vtk.js/IO/Misc/OBJReader.js';
+// bring pdb definition (big)
 import '@kitware/vtk.js/IO/Misc/PDBReader.js';
+// bring zip (big++)
 import '@kitware/vtk.js/IO/XML/XMLImageDataReader.js';
 import '@kitware/vtk.js/IO/XML/XMLPolyDataReader.js';