diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index a845d10..6a3a7ca 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -20,6 +20,7 @@ jobs:
             3.2,
             3.3,
             3.4,
+            '4.0',
             jruby,
           ]
         exclude:
diff --git a/Gemfile.lock b/Gemfile.lock
index 96c88c2..e2c5045 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -12,25 +12,25 @@ GEM
     addressable (2.8.8)
       public_suffix (>= 2.0.2, < 8.0)
     ast (2.4.3)
-    bigdecimal (3.3.1)
-    bigdecimal (3.3.1-java)
+    bigdecimal (4.0.1)
+    bigdecimal (4.0.1-java)
     connection_pool (3.0.2)
     crack (1.0.1)
       bigdecimal
       rexml
     domain_name (0.6.20240107)
-    ffi (1.17.2)
-    ffi (1.17.2-aarch64-linux-gnu)
-    ffi (1.17.2-aarch64-linux-musl)
-    ffi (1.17.2-arm-linux-gnu)
-    ffi (1.17.2-arm-linux-musl)
-    ffi (1.17.2-arm64-darwin)
-    ffi (1.17.2-java)
-    ffi (1.17.2-x86-linux-gnu)
-    ffi (1.17.2-x86-linux-musl)
-    ffi (1.17.2-x86_64-darwin)
-    ffi (1.17.2-x86_64-linux-gnu)
-    ffi (1.17.2-x86_64-linux-musl)
+    ffi (1.17.3)
+    ffi (1.17.3-aarch64-linux-gnu)
+    ffi (1.17.3-aarch64-linux-musl)
+    ffi (1.17.3-arm-linux-gnu)
+    ffi (1.17.3-arm-linux-musl)
+    ffi (1.17.3-arm64-darwin)
+    ffi (1.17.3-java)
+    ffi (1.17.3-x86-linux-gnu)
+    ffi (1.17.3-x86-linux-musl)
+    ffi (1.17.3-x86_64-darwin)
+    ffi (1.17.3-x86_64-linux-gnu)
+    ffi (1.17.3-x86_64-linux-musl)
     ffi-compiler (1.3.2)
       ffi (>= 1.15.5)
       rake
@@ -54,11 +54,11 @@ GEM
     minitest (6.0.1)
       prism (~> 1.5)
     parallel (1.27.0)
-    parser (3.3.10.0)
+    parser (3.3.10.1)
       ast (~> 2.4.1)
       racc
-    prism (1.7.0)
-    public_suffix (7.0.0)
+    prism (1.9.0)
+    public_suffix (7.0.2)
     racc (1.8.1)
     racc (1.8.1-java)
     rainbow (3.1.1)