diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index e123506..bc160fd 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -90,7 +90,7 @@ importers:
         version: 14.2.7(eslint@8.57.0)(typescript@5.5.4)
       readium-css:
         specifier: github:readium/readium-css#theming-improvements
-        version: https://codeload.github.com/readium/readium-css/tar.gz/6df67526efd2f886ac68ba9e0d80042d86de57e2
+        version: https://codeload.github.com/readium/readium-css/tar.gz/37e4f03de83316b9752c4a9c76329d2a0062922e
       typescript:
         specifier: ^5
         version: 5.5.4
@@ -3405,8 +3405,8 @@ packages:
     resolution: {integrity: sha512-GkMg9uOTpIWWKbSsgwb5fA4EavTR+SG/PMPoAY8hkhHfEEY0/vqljY+XHqtDf2cr2IJtoNRDbrrEpZUiZCkYRw==}
     engines: {node: '>= 14.16.0'}
 
-  readium-css@https://codeload.github.com/readium/readium-css/tar.gz/6df67526efd2f886ac68ba9e0d80042d86de57e2:
-    resolution: {tarball: https://codeload.github.com/readium/readium-css/tar.gz/6df67526efd2f886ac68ba9e0d80042d86de57e2}
+  readium-css@https://codeload.github.com/readium/readium-css/tar.gz/37e4f03de83316b9752c4a9c76329d2a0062922e:
+    resolution: {tarball: https://codeload.github.com/readium/readium-css/tar.gz/37e4f03de83316b9752c4a9c76329d2a0062922e}
     version: 2.0.0-alpha.10
 
   redux-thunk@3.1.0:
@@ -8258,7 +8258,7 @@ snapshots:
 
   readdirp@4.0.1: {}
 
-  readium-css@https://codeload.github.com/readium/readium-css/tar.gz/6df67526efd2f886ac68ba9e0d80042d86de57e2: {}
+  readium-css@https://codeload.github.com/readium/readium-css/tar.gz/37e4f03de83316b9752c4a9c76329d2a0062922e: {}
 
   redux-thunk@3.1.0(redux@5.0.1):
     dependencies:
diff --git a/src/readium/ts-toolkit b/src/readium/ts-toolkit
index 47cc4cd..d8ef603 160000
--- a/src/readium/ts-toolkit
+++ b/src/readium/ts-toolkit
@@ -1 +1 @@
-Subproject commit 47cc4cd18bf666f1029cbaae0c76a50a2ea6059f
+Subproject commit d8ef603316105c666d719a8353b676685df51f84