diff --git a/org.eclipse.m2e.editor.lemminx.tests/.classpath b/org.eclipse.m2e.editor.lemminx.tests/.classpath
index 427e49b0d4..c9bfedfe9c 100644
--- a/org.eclipse.m2e.editor.lemminx.tests/.classpath
+++ b/org.eclipse.m2e.editor.lemminx.tests/.classpath
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-17">
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-21">
 		<attributes>
 			<attribute name="module" value="true"/>
 		</attributes>
diff --git a/org.eclipse.m2e.editor.lemminx.tests/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.m2e.editor.lemminx.tests/.settings/org.eclipse.jdt.core.prefs
index 62ef3488cc..23fa13b170 100644
--- a/org.eclipse.m2e.editor.lemminx.tests/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.m2e.editor.lemminx.tests/.settings/org.eclipse.jdt.core.prefs
@@ -1,9 +1,9 @@
 eclipse.preferences.version=1
-org.eclipse.jdt.core.compiler.codegen.targetPlatform=17
-org.eclipse.jdt.core.compiler.compliance=17
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=21
+org.eclipse.jdt.core.compiler.compliance=21
 org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
 org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
 org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
 org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=warning
 org.eclipse.jdt.core.compiler.release=enabled
-org.eclipse.jdt.core.compiler.source=17
+org.eclipse.jdt.core.compiler.source=21
diff --git a/org.eclipse.m2e.editor.lemminx.tests/META-INF/MANIFEST.MF b/org.eclipse.m2e.editor.lemminx.tests/META-INF/MANIFEST.MF
index f2b6fc5368..4e9ab741b3 100644
--- a/org.eclipse.m2e.editor.lemminx.tests/META-INF/MANIFEST.MF
+++ b/org.eclipse.m2e.editor.lemminx.tests/META-INF/MANIFEST.MF
@@ -4,7 +4,7 @@ Bundle-Name: M2E Maven POM File Editor using Wild Web Developer, Lemminx and Mav
 Bundle-SymbolicName: org.eclipse.m2e.editor.lemminx.tests
 Bundle-Version: 2.0.2.qualifier
 Automatic-Module-Name: org.eclipse.m2e.editor.lemminx.tests
-Bundle-RequiredExecutionEnvironment: JavaSE-17
+Bundle-RequiredExecutionEnvironment: JavaSE-21
 Bundle-Vendor: Eclipse.org - m2e
 Fragment-Host: org.eclipse.m2e.editor.lemminx
 Require-Bundle: org.junit,
diff --git a/org.eclipse.m2e.editor.lemminx/.classpath b/org.eclipse.m2e.editor.lemminx/.classpath
index 3628e33687..35386b94bb 100644
--- a/org.eclipse.m2e.editor.lemminx/.classpath
+++ b/org.eclipse.m2e.editor.lemminx/.classpath
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-17">
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-21">
 		<attributes>
 			<attribute name="module" value="true"/>
 		</attributes>
diff --git a/org.eclipse.m2e.editor.lemminx/.settings/org.eclipse.jdt.core.prefs b/org.eclipse.m2e.editor.lemminx/.settings/org.eclipse.jdt.core.prefs
index d4540a53f9..3a79233b13 100644
--- a/org.eclipse.m2e.editor.lemminx/.settings/org.eclipse.jdt.core.prefs
+++ b/org.eclipse.m2e.editor.lemminx/.settings/org.eclipse.jdt.core.prefs
@@ -1,10 +1,10 @@
 eclipse.preferences.version=1
 org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
-org.eclipse.jdt.core.compiler.codegen.targetPlatform=17
-org.eclipse.jdt.core.compiler.compliance=17
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=21
+org.eclipse.jdt.core.compiler.compliance=21
 org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
 org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
 org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
 org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=warning
 org.eclipse.jdt.core.compiler.release=enabled
-org.eclipse.jdt.core.compiler.source=17
+org.eclipse.jdt.core.compiler.source=21
diff --git a/org.eclipse.m2e.editor.lemminx/META-INF/MANIFEST.MF b/org.eclipse.m2e.editor.lemminx/META-INF/MANIFEST.MF
index c689eb6472..2a1752d0f6 100644
--- a/org.eclipse.m2e.editor.lemminx/META-INF/MANIFEST.MF
+++ b/org.eclipse.m2e.editor.lemminx/META-INF/MANIFEST.MF
@@ -15,5 +15,5 @@ Require-Bundle: org.eclipse.wildwebdeveloper.xml;bundle-version="[1.3,1.4)",
  org.eclipse.m2e.core,
  org.eclipse.m2e.maven.runtime;bundle-version="[3.8.6,4.0.0)",
  org.eclipse.core.resources
-Bundle-RequiredExecutionEnvironment: JavaSE-17
+Bundle-RequiredExecutionEnvironment: JavaSE-21
 Bundle-Vendor: Eclipse.org - m2e