diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 856321723..b53d54936 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -45,11 +45,11 @@ jobs:
 
     # Java setup step completes very fast, no need to run in a preconfigured docker container.
     # CodeQL is intended to detect any Java toolchains added to the execution environment.
-    - name: Set up JDK 20
+    - name: Set up JDK 21
       uses: actions/setup-java@v3
       with:
-        distribution: temurin
-        java-version: 20
+        distribution: corretto
+        java-version: 21
         cache: gradle
 
     # Initializes the CodeQL tools for scanning.
diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index 408507570..210f8ba58 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -32,10 +32,10 @@ jobs:
       with:
         fetch-depth: 0
     # Java setup step completes very fast, no need to run in a preconfigured docker container.
-    - name: Set up JDK 20
+    - name: Set up JDK 21
       uses: actions/setup-java@v3
       with:
-        distribution: temurin
+        distribution: corretto
         java-version: 20
         cache: gradle
     - name: Show version string
diff --git a/LICENSE b/LICENSE
index dbe6da4ec..f845c96e3 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2020 Conveyal
+Copyright (c) 2020-2023 Conveyal
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/build.gradle b/build.gradle
index 3397237c1..7bc3a4fff 100644
--- a/build.gradle
+++ b/build.gradle
@@ -11,12 +11,12 @@ version gitVersion()
 
 java {
     toolchain {
-        languageVersion.set(JavaLanguageVersion.of(20))
+        languageVersion.set(JavaLanguageVersion.of(21))
     }
 }
 
 jar {
-    // For Java 11 Modules, specify a module name.
+    // For Java 11+ Modules, specify a module name.
     // Do not create module-info.java until all our dependencies specify a module name.
     // Main-Class BackendMain will start a local backend.
     // Build-Jdk-Spec mimics a Maven manifest entry that helps us automatically install the right JVM.