diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8c7c8dc15b..3c979aa268 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -81,7 +81,7 @@ jobs:
       if: matrix.benchmark == false
       uses: actions/setup-java@v4
       with:
-        java-version: 17
+        java-version: 21
         distribution: 'adopt'
 
     - name: Install Python
@@ -243,7 +243,7 @@ jobs:
   #     if: matrix.benchmark == false
   #     uses: actions/setup-java@v4
   #     with:
-  #       java-version: 17
+  #       java-version: 21
   #       distribution: 'temurin'
   #   - name: Install Python
   #     uses: actions/setup-python@v5
diff --git a/build.py b/build.py
index 9ca9759b84..18132ee491 100755
--- a/build.py
+++ b/build.py
@@ -89,10 +89,11 @@ def Exit( self ):
   )$
 """
 
-JDTLS_MILESTONE = '1.40.0'
-JDTLS_BUILD_STAMP = '202409261450'
+JDTLS_REQUIRED_JAVA_VERSION = 21
+JDTLS_MILESTONE = '1.51.0'
+JDTLS_BUILD_STAMP = '202510022025'
 JDTLS_SHA256 = (
-  '7416fc62befa450e32f06ec2b503f2eec5f22f0b1cc12f7b8ee5112bf671cf11'
+  '8a59372117881bf5bdc0220f2254472846b88137c058f344b00a7d41427745a1'
 )
 
 DEFAULT_RUST_TOOLCHAIN = 'nightly-2024-12-12'
@@ -1110,7 +1111,7 @@ def Print( *args, **kwargs ):
     sys.stdout.write( 'Installing jdt.ls for Java support...' )
     sys.stdout.flush()
 
-  CheckJavaVersion( 17 )
+  CheckJavaVersion( JDTLS_REQUIRED_JAVA_VERSION )
 
   TARGET = p.join( DIR_OF_THIRD_PARTY, 'eclipse.jdt.ls', 'target', )
   REPOSITORY = p.join( TARGET, 'repository' )