diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 1b33c55baa..8bdaf60c75 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 7705927e94..26dec6cde0 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-bin.zip
+distributionSha256Sum=a17ddd85a26b6a7f5ddb71ff8b05fc5104c0202c6e64782429790c933686c806
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
diff --git a/gradlew b/gradlew
index 23d15a9367..adff685a03 100755
--- a/gradlew
+++ b/gradlew
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 #
-# Copyright © 2015-2021 the original authors.
+# Copyright © 2015 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -114,7 +114,6 @@ case "$( uname )" in                #(
   NONSTOP* )        nonstop=true ;;
 esac
 
-CLASSPATH="\\\"\\\""
 
 
 # Determine the Java command to use to start the JVM.
@@ -172,7 +171,6 @@ fi
 # For Cygwin or MSYS, switch paths to Windows format before running java
 if "$cygwin" || "$msys" ; then
     APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
-    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
 
     JAVACMD=$( cygpath --unix "$JAVACMD" )
 
@@ -212,7 +210,6 @@ DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
-        -classpath "$CLASSPATH" \
         -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
         "$@"
 
diff --git a/gradlew.bat b/gradlew.bat
index 5eed7ee845..e509b2dd8f 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -70,11 +70,10 @@ goto fail
 :execute
 @rem Setup the command line
 
-set CLASSPATH=
 
 
 @rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
 
 :end
 @rem End local scope for the variables with windows NT shell
diff --git a/wire-gradle-plugin/src/test/projects/java-project-java-protos/build.gradle b/wire-gradle-plugin/src/test/projects/java-project-java-protos/build.gradle
index 278b589879..762605f970 100644
--- a/wire-gradle-plugin/src/test/projects/java-project-java-protos/build.gradle
+++ b/wire-gradle-plugin/src/test/projects/java-project-java-protos/build.gradle
@@ -15,7 +15,7 @@ buildscript {
 apply plugin: 'application'
 apply plugin: 'com.squareup.wire'
 
-mainClassName = 'com.squareup.dinosaurs.Sample'
+application.mainClass = "com.squareup.dinosaurs.Sample"
 
 repositories {
   maven {
diff --git a/wire-gradle-plugin/src/test/projects/java-project-kotlin-protos/build.gradle b/wire-gradle-plugin/src/test/projects/java-project-kotlin-protos/build.gradle
index 972cbe6ae2..833e41f5ed 100644
--- a/wire-gradle-plugin/src/test/projects/java-project-kotlin-protos/build.gradle
+++ b/wire-gradle-plugin/src/test/projects/java-project-kotlin-protos/build.gradle
@@ -19,7 +19,7 @@ apply plugin: 'application'
 apply plugin: 'org.jetbrains.kotlin.jvm'
 apply plugin: 'com.squareup.wire'
 
-mainClassName = 'com.squareup.dinosaurs.Sample'
+application.mainClass = "com.squareup.dinosaurs.Sample"
 
 repositories {
   maven {
diff --git a/wire-gradle-plugin/src/test/projects/kotlin-project-java-protos/build.gradle b/wire-gradle-plugin/src/test/projects/kotlin-project-java-protos/build.gradle
index 33dd16de0e..71c9b3dd20 100644
--- a/wire-gradle-plugin/src/test/projects/kotlin-project-java-protos/build.gradle
+++ b/wire-gradle-plugin/src/test/projects/kotlin-project-java-protos/build.gradle
@@ -19,7 +19,7 @@ apply plugin: 'application'
 apply plugin: 'org.jetbrains.kotlin.jvm'
 apply plugin: 'com.squareup.wire'
 
-mainClassName = 'com.squareup.dinosaurs.Sample'
+application.mainClass = "com.squareup.dinosaurs.Sample"
 
 repositories {
   maven {
diff --git a/wire-gradle-plugin/src/test/projects/kotlin-project-kotlin-protos/build.gradle b/wire-gradle-plugin/src/test/projects/kotlin-project-kotlin-protos/build.gradle
index 3a9b075bb1..3c1ad7d01a 100644
--- a/wire-gradle-plugin/src/test/projects/kotlin-project-kotlin-protos/build.gradle
+++ b/wire-gradle-plugin/src/test/projects/kotlin-project-kotlin-protos/build.gradle
@@ -19,7 +19,8 @@ apply plugin: 'application'
 apply plugin: 'org.jetbrains.kotlin.jvm'
 apply plugin: 'com.squareup.wire'
 
-mainClassName = 'com.squareup.dinosaurs.Sample'
+application.mainClass = "com.squareup.dinosaurs.Sample"
+
 
 repositories {
   maven {
diff --git a/wire-gradle-plugin/src/test/projects/sourcedir-exclude/build.gradle b/wire-gradle-plugin/src/test/projects/sourcedir-exclude/build.gradle
index dd45598c5e..d1f0379e1e 100644
--- a/wire-gradle-plugin/src/test/projects/sourcedir-exclude/build.gradle
+++ b/wire-gradle-plugin/src/test/projects/sourcedir-exclude/build.gradle
@@ -19,7 +19,7 @@ apply plugin: 'application'
 apply plugin: 'org.jetbrains.kotlin.jvm'
 apply plugin: 'com.squareup.wire'
 
-mainClassName = 'com.squareup.dinosaurs.Sample'
+application.mainClass = "com.squareup.dinosaurs.Sample"
 
 repositories {
   maven {
diff --git a/wire-gradle-plugin/src/test/projects/sourcedir-include/build.gradle b/wire-gradle-plugin/src/test/projects/sourcedir-include/build.gradle
index 7a8c60504e..e4edf6a54a 100644
--- a/wire-gradle-plugin/src/test/projects/sourcedir-include/build.gradle
+++ b/wire-gradle-plugin/src/test/projects/sourcedir-include/build.gradle
@@ -19,7 +19,7 @@ apply plugin: 'application'
 apply plugin: 'org.jetbrains.kotlin.jvm'
 apply plugin: 'com.squareup.wire'
 
-mainClassName = 'com.squareup.dinosaurs.Sample'
+application.mainClass = "com.squareup.dinosaurs.Sample"
 
 repositories {
   maven {