diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7fad255..f881d27 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
-      - uses: actions/setup-java@v4
+      - uses: actions/setup-java@v5
         with:
           distribution: temurin
           java-version: 21
@@ -65,7 +65,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
-      - uses: actions/setup-java@v4
+      - uses: actions/setup-java@v5
         with:
           distribution: temurin
           java-version: 21
@@ -91,7 +91,7 @@ jobs:
           set -euo pipefail
           shopt -s nullglob
           reports=plugin/build/reports/pluginVerifier
-          declared=$(grep -c '^ *ide("' plugin/build.gradle.kts)
+          declared=$(grep -c '^ *create(IntelliJPlatformType' plugin/build.gradle.kts)
           dirs=("$reports"/*/)
           echo "declared=$declared verified=${#dirs[@]}"
           if [ "${#dirs[@]}" -ne "$declared" ]; then
diff --git a/core/build.gradle.kts b/core/build.gradle.kts
index 0d147f6..c3365e2 100644
--- a/core/build.gradle.kts
+++ b/core/build.gradle.kts
@@ -12,7 +12,7 @@ repositories {
 
 dependencies {
     testImplementation("org.junit.jupiter:junit-jupiter:6.1.2")
-    testImplementation("org.assertj:assertj-core:3.27.0")
+    testImplementation("org.assertj:assertj-core:3.27.7")
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
 }
 
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index df97d72..a351597 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.10.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.6.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
diff --git a/plugin/build.gradle.kts b/plugin/build.gradle.kts
index 26b8923..fc3d793 100644
--- a/plugin/build.gradle.kts
+++ b/plugin/build.gradle.kts
@@ -1,6 +1,8 @@
+import org.jetbrains.intellij.platform.gradle.IntelliJPlatformType
+
 plugins {
     id("java")
-    id("org.jetbrains.intellij.platform") version "2.1.0"
+    id("org.jetbrains.intellij.platform") version "2.18.1"
 }
 
 java {
@@ -43,12 +45,13 @@ intellijPlatform {
     // the compile target cannot show. untilBuild stays unverified on purpose: 261 has no
     // release to check against, so it remains a forward-looking promise.
     //
-    // Use the string notation. The ide(IntelliJPlatformType, String) overload accepts these
-    // versions and then schedules nothing, leaving a green run that verified one IDE.
+    // create(type, version), not ide(...). On 2.1.0 the ide(String) notation worked and the
+    // typed overload silently scheduled nothing; 2.18.1 removed ide() altogether, so the same
+    // mistake is now a compile error rather than a green run that verified one IDE.
     pluginVerification {
         ides {
-            ide("IC-2024.2.5") // the floor sinceBuild = 242 claims
-            ide("IC-2024.3.5") // what the plugin compiles against
+            create(IntelliJPlatformType.IntellijIdeaCommunity, "2024.2.5") // the sinceBuild = 242 floor
+            create(IntelliJPlatformType.IntellijIdeaCommunity, "2024.3.5") // the compile target
         }
     }
 }