diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index a255cd5..ab3296e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -13,6 +13,7 @@ jobs:
           - '3.1'
           - '3.2'
           - '3.3'
+          - '3.4'
           - truffleruby
     runs-on: ubuntu-latest
     steps:
diff --git a/demo/Gemfile.lock b/demo/Gemfile.lock
index bd5bcd8..0c35d66 100644
--- a/demo/Gemfile.lock
+++ b/demo/Gemfile.lock
@@ -8,8 +8,17 @@ GEM
       rexml (~> 3.2.5)
       rinku (~> 2.0)
     diff-lcs (1.5.1)
+    ffi (1.17.1)
+    ffi (1.17.1-aarch64-linux-gnu)
+    ffi (1.17.1-aarch64-linux-musl)
+    ffi (1.17.1-arm-linux-gnu)
+    ffi (1.17.1-arm-linux-musl)
+    ffi (1.17.1-arm64-darwin)
+    ffi (1.17.1-x86-linux-gnu)
+    ffi (1.17.1-x86-linux-musl)
     ffi (1.17.1-x86_64-darwin)
     ffi (1.17.1-x86_64-linux-gnu)
+    ffi (1.17.1-x86_64-linux-musl)
     gemoji (4.0.1)
     json (2.9.1)
     language_server-protocol (3.17.0.3)
@@ -75,8 +84,17 @@ GEM
     unicode-emoji (4.0.4)
 
 PLATFORMS
-  x86_64-darwin-19
-  x86_64-linux
+  aarch64-linux-gnu
+  aarch64-linux-musl
+  arm-linux-gnu
+  arm-linux-musl
+  arm64-darwin
+  ruby
+  x86-linux-gnu
+  x86-linux-musl
+  x86_64-darwin
+  x86_64-linux-gnu
+  x86_64-linux-musl
 
 DEPENDENCIES
   auto_html
@@ -90,4 +108,4 @@ DEPENDENCIES
   tilt
 
 BUNDLED WITH
-   2.2.32
+   2.6.2