diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index 985b842c..809ac522 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -22,7 +22,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [ '11', '17', '20' ]
+        java: [ '11', '21' ]
 
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/javadocs.yml b/.github/workflows/javadocs.yml
index 048ed04d..782978c5 100644
--- a/.github/workflows/javadocs.yml
+++ b/.github/workflows/javadocs.yml
@@ -22,10 +22,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v3
         with:
-          java-version: 17
+          java-version: 21
           distribution: 'temurin'
       - name: Grant execute permission for gradlew
         run: chmod +x gradlew
diff --git a/build.gradle.kts b/build.gradle.kts
index b2651037..73081663 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -120,8 +120,8 @@ To find all missing javadocs / all javadocs warnings execute this command:
 javadoc.apply {
     isFailOnError = isCI
 
-    //Javadocs are scuffed on these version I don't know and care why.
-    if (javaVersion <= JavaVersion.VERSION_13) {
+    //Fixes the error where the executor could not be found and the build fails.
+    if (javaVersion <= JavaVersion.VERSION_20) {
         isFailOnError = false
     }
 
@@ -141,7 +141,7 @@ javadoc.apply {
         if (javaVersion >= JavaVersion.VERSION_13) {
             opt.addBooleanOption("Xdoclint:all", true)
         } else {
-            //Can be ignored because JavaDocs are generated using Java 17.
+            //Can be ignored because JavaDocs are generated using Java 21.
             opt.addBooleanOption("Xdoclint:all,-missing,-accessibility", true)
         }
     }
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index c1962a79..7f93135c 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 17a8ddce..3fa8f862 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-8.2.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index aeb74cbb..0adc8e1a 100644
--- a/gradlew
+++ b/gradlew
@@ -83,7 +83,8 @@ done
 # This is normally unused
 # shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -130,10 +131,13 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.