diff --git a/package-lock.json b/package-lock.json
index 6526dc668f..e97e35beb4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -19127,7 +19127,7 @@
         "postprocessing": "^6.38.2"
       },
       "devDependencies": {
-        "@google/model-viewer": "^4.2.0",
+        "@google/model-viewer": "^4.3.1",
         "@rollup/plugin-commonjs": "^28.0.3",
         "@rollup/plugin-node-resolve": "^16.0.0",
         "@rollup/plugin-replace": "^6.0.2",
@@ -19156,7 +19156,7 @@
         "node": ">=6.0.0"
       },
       "peerDependencies": {
-        "@google/model-viewer": "^4.2.0"
+        "@google/model-viewer": "^4.3.1"
       }
     },
     "packages/modelviewer.dev": {
@@ -19164,7 +19164,7 @@
       "version": "0.0.1",
       "license": "Apache-2.0",
       "dependencies": {
-        "@google/model-viewer": "^4.2.0",
+        "@google/model-viewer": "^4.3.1",
         "@google/model-viewer-effects": "^1.4.0",
         "@types/prismjs": "^1.26.5",
         "focus-visible": "^5.2.1",
@@ -19189,7 +19189,7 @@
       "license": "Apache-2.0",
       "dependencies": {
         "@actions/core": "^1.11.1",
-        "@google/model-viewer": "^4.2.0",
+        "@google/model-viewer": "^4.3.1",
         "@polymer/paper-button": "^3.0.1",
         "@polymer/paper-radio-group": "^3.0.1",
         "@polymer/paper-slider": "^3.0.1",
@@ -19226,7 +19226,7 @@
         "@gltf-transform/core": "^4.1.2",
         "@gltf-transform/extensions": "^4.1.2",
         "@gltf-transform/functions": "^4.1.2",
-        "@google/model-viewer": "^4.2.0",
+        "@google/model-viewer": "^4.3.1",
         "@material/mwc-button": "^0.27.0",
         "@material/mwc-checkbox": "^0.27.0",
         "@material/mwc-dialog": "^0.27.0",
diff --git a/packages/model-viewer-effects/package.json b/packages/model-viewer-effects/package.json
index d6129f71c7..3eb6a4653d 100644
--- a/packages/model-viewer-effects/package.json
+++ b/packages/model-viewer-effects/package.json
@@ -76,10 +76,10 @@
     "postprocessing": "^6.38.2"
   },
   "peerDependencies": {
-    "@google/model-viewer": "^4.2.0"
+    "@google/model-viewer": "^4.3.1"
   },
   "devDependencies": {
-    "@google/model-viewer": "^4.2.0",
+    "@google/model-viewer": "^4.3.1",
     "@rollup/plugin-commonjs": "^28.0.3",
     "@rollup/plugin-node-resolve": "^16.0.0",
     "@rollup/plugin-replace": "^6.0.2",
diff --git a/packages/modelviewer.dev/package.json b/packages/modelviewer.dev/package.json
index 12547e3f96..756a49f446 100644
--- a/packages/modelviewer.dev/package.json
+++ b/packages/modelviewer.dev/package.json
@@ -25,7 +25,7 @@
     "node": ">=6.0.0"
   },
   "dependencies": {
-    "@google/model-viewer": "^4.2.0",
+    "@google/model-viewer": "^4.3.1",
     "@google/model-viewer-effects": "^1.4.0",
     "@types/prismjs": "^1.26.5",
     "focus-visible": "^5.2.1",
diff --git a/packages/modelviewer.dev/scripts/update-versions.js b/packages/modelviewer.dev/scripts/update-versions.js
index 1d477329b1..e0f1549857 100644
--- a/packages/modelviewer.dev/scripts/update-versions.js
+++ b/packages/modelviewer.dev/scripts/update-versions.js
@@ -24,6 +24,7 @@ const CONFIG = {
         '../dist/data/docs.json',
         '../dist/examples/postprocessing/index.html',
         '../dist/examples/twitter/player.html',
+        '../dist/dist/space-opera.js',
     ].map(file => path.resolve(__dirname, file)),
     placeholders: {
         modelViewer: '{{MODELVIEWER_VERSION}}',
diff --git a/packages/render-fidelity-tools/package.json b/packages/render-fidelity-tools/package.json
index 231bfd9293..d499cc772d 100644
--- a/packages/render-fidelity-tools/package.json
+++ b/packages/render-fidelity-tools/package.json
@@ -23,7 +23,7 @@
   },
   "dependencies": {
     "@actions/core": "^1.11.1",
-    "@google/model-viewer": "^4.2.0",
+    "@google/model-viewer": "^4.3.1",
     "@polymer/paper-button": "^3.0.1",
     "@polymer/paper-radio-group": "^3.0.1",
     "@polymer/paper-slider": "^3.0.1",
diff --git a/packages/space-opera/package.json b/packages/space-opera/package.json
index 2c02d9ea3e..8ada20c2da 100644
--- a/packages/space-opera/package.json
+++ b/packages/space-opera/package.json
@@ -38,7 +38,7 @@
     "@gltf-transform/core": "^4.1.2",
     "@gltf-transform/extensions": "^4.1.2",
     "@gltf-transform/functions": "^4.1.2",
-    "@google/model-viewer": "^4.2.0",
+    "@google/model-viewer": "^4.3.1",
     "@material/mwc-button": "^0.27.0",
     "@material/mwc-checkbox": "^0.27.0",
     "@material/mwc-dialog": "^0.27.0",
diff --git a/scripts/dev-server.js b/scripts/dev-server.js
index afa7f863da..c98ea63392 100644
--- a/scripts/dev-server.js
+++ b/scripts/dev-server.js
@@ -147,8 +147,8 @@ const server = http.createServer((req, res) => {
       let contentType = mimeTypes[extname] || 'application/octet-stream';
       res.writeHead(200, { 'Content-Type': contentType });
 
-      // Dynamically replace placeholders in HTML and JSON files!
-      if (extname === '.html' || extname === '.json') {
+      // Dynamically replace placeholders in HTML, JSON, and space-opera files!
+      if (extname === '.html' || extname === '.json' || filePath.endsWith('space-opera.js') || filePath.endsWith('constants.js')) {
         let text = content.toString('utf8');
         for (const [placeholder, value] of Object.entries(replacements)) {
           text = text.replaceAll(placeholder, value);