diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 536988c8b..debf4dd63 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -14,7 +14,7 @@ jobs:
       - uses: actions/setup-java@v6
         with:
           distribution: temurin
-          java-version: 17.0.21+9
+          java-version: 25.0.5+8.0.LTS
 
       - uses: gradle/actions/setup-gradle@v6
         with:
@@ -31,7 +31,7 @@ jobs:
       - uses: actions/setup-java@v6
         with:
           distribution: temurin
-          java-version: 17.0.21+9
+          java-version: 25.0.5+8.0.LTS
 
       - uses: gradle/actions/setup-gradle@v6
         with:
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 85c7f09c1..8eb4ccd54 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -62,6 +62,9 @@ These are the main components of the project.
 | `gradle spotlessApply`                                  | terminal | Format Java and Kotlin sources with Spotless.                            |
 | `gradle spotlessCheck`                                  | terminal | Check Java and Kotlin formatting. Enforced by GitHub Actions.            |
 
+Spotless needs JDK 21 or newer for google-java-format; from the default JDK 17
+shell, run it as `nix develop .#jdk25 --command gradle spotlessApply`.
+
 ## Import the project into IntelliJ
 
 It's recommended to use IntelliJ when editing code in this codebase.
diff --git a/build.gradle.kts b/build.gradle.kts
index 05bc3d8b4..01cc930fa 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -14,7 +14,7 @@ spotless {
     java {
         target("scip-*/src/**/*.java")
         targetExclude("scip-java/src/test/resources/fixtures/**")
-        googleJavaFormat("1.28.0")
+        googleJavaFormat("1.36.1")
     }
 
     kotlin {