diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/dom/ASTConverter_15Test.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/dom/ASTConverter_15Test.java
index 99fab78..c374727 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/dom/ASTConverter_15Test.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/dom/ASTConverter_15Test.java
@@ -760,7 +760,7 @@
 		assertEquals("wrong line number", 9, compilationUnit.getLineNumber(node.getStartPosition()));
 	}
 
-	public void _testPatternInstanceOfExpression001() throws JavaModelException {
+	public void testPatternInstanceOfExpression001() throws JavaModelException {
 		if (!isJRE15) {
 			System.err.println("Test "+getName()+" requires a JRE 15");
 			return;
@@ -795,14 +795,14 @@
 				checkSourceRange(expression, "o instanceof String s", contents);
 				assertEquals("Not an instanceof expression", ASTNode.INSTANCEOF_EXPRESSION, expression.getNodeType());
 				InstanceofExpression instanceofExpression = (InstanceofExpression) expression;
-				SingleVariableDeclaration var = instanceofExpression.getPatternVariable();
-				checkSourceRange(var, "String s", contents);
+				SimpleName var = instanceofExpression.getPatternVariable();
+				checkSourceRange(var, "s", contents);
 			}finally {
 				javaProject.setOption(JavaCore.COMPILER_PB_ENABLE_PREVIEW_FEATURES, old);
 			}
 	}
 
-	public void _testPatternInstanceOfExpression002() throws JavaModelException {
+	public void testPatternInstanceOfExpression002() throws JavaModelException {
 		if (!isJRE15) {
 			System.err.println("Test "+getName()+" requires a JRE 15");
 			return;
@@ -838,7 +838,7 @@
 				checkSourceRange(expression, "o instanceof String", contents);
 				assertEquals("Not an instanceof expression", ASTNode.INSTANCEOF_EXPRESSION, expression.getNodeType());
 				InstanceofExpression instanceofExpression = (InstanceofExpression) expression;
-				SingleVariableDeclaration var = instanceofExpression.getPatternVariable();
+				SimpleName var = instanceofExpression.getPatternVariable();
 				assertNull(var);
 			}finally {
 				javaProject.setOption(JavaCore.COMPILER_PB_ENABLE_PREVIEW_FEATURES, old);
diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/rewrite/describing/ASTRewritingInstanceOfPatternExpressionTest.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/rewrite/describing/ASTRewritingInstanceOfPatternExpressionTest.java
index ce33099..d9ed1b5 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/rewrite/describing/ASTRewritingInstanceOfPatternExpressionTest.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/rewrite/describing/ASTRewritingInstanceOfPatternExpressionTest.java
@@ -26,7 +26,6 @@
 import org.eclipse.jdt.core.dom.InstanceofExpression;
 import org.eclipse.jdt.core.dom.MethodDeclaration;
 import org.eclipse.jdt.core.dom.SimpleType;
-import org.eclipse.jdt.core.dom.SingleVariableDeclaration;
 import org.eclipse.jdt.core.dom.TypeDeclaration;
 import org.eclipse.jdt.core.dom.rewrite.ASTRewrite;
 
@@ -90,10 +89,7 @@
 			instanceOfExpression.setLeftOperand(ast.newSimpleName("o"));//$NON-NLS-1$
 			SimpleType simpleType = ast.newSimpleType(ast.newSimpleName("String"));//$NON-NLS-1$
 			instanceOfExpression.setRightOperand(simpleType);
-			SingleVariableDeclaration patternVariable = ast.newSingleVariableDeclaration();
-			patternVariable.setName(ast.newSimpleName("s"));
-			patternVariable.setType(ast.newSimpleType(ast.newSimpleName("String")));//$NON-NLS-1$
-			instanceOfExpression.setPatternVariable(patternVariable);
+			instanceOfExpression.setPatternVariable(ast.newSimpleName("s"));
 			ifStatement.setExpression(instanceOfExpression);
 			ifStatement.setThenStatement(ast.newEmptyStatement());
 			rewrite.getListRewrite(block, Block.STATEMENTS_PROPERTY).insertLast(ifStatement, null);
diff --git a/org.eclipse.jdt.core/dom/org/eclipse/jdt/core/dom/ASTConverter.java b/org.eclipse.jdt.core/dom/org/eclipse/jdt/core/dom/ASTConverter.java
index 430be8a..76adab1 100644
--- a/org.eclipse.jdt.core/dom/org/eclipse/jdt/core/dom/ASTConverter.java
+++ b/org.eclipse.jdt.core/dom/org/eclipse/jdt/core/dom/ASTConverter.java
@@ -2225,7 +2225,8 @@
 		int startPosition = leftExpression.getStartPosition();
 		int sourceEnd = convertType.getStartPosition() + convertType.getLength() - 1;
 		if (DOMASTUtil.isInstanceofExpressionPatternSupported(this.ast) && expression.elementVariable != null) {
-			instanceOfExpression.setPatternVariable(convertToSingleVariableDeclaration(expression.elementVariable));
+			SingleVariableDeclaration patternVariable = convertToSingleVariableDeclaration(expression.elementVariable);
+			instanceOfExpression.setPatternVariable(((SimpleName)patternVariable.getName().clone(this.ast)));
 			sourceEnd= expression.elementVariable.sourceEnd;
 		}
 		instanceOfExpression.setSourceRange(startPosition, sourceEnd - startPosition + 1);
diff --git a/org.eclipse.jdt.core/dom/org/eclipse/jdt/core/dom/InstanceofExpression.java b/org.eclipse.jdt.core/dom/org/eclipse/jdt/core/dom/InstanceofExpression.java
index 12ea6c7..9bd4ef8 100644
--- a/org.eclipse.jdt.core/dom/org/eclipse/jdt/core/dom/InstanceofExpression.java
+++ b/org.eclipse.jdt.core/dom/org/eclipse/jdt/core/dom/InstanceofExpression.java
@@ -47,12 +47,13 @@
 		new ChildPropertyDescriptor(InstanceofExpression.class, "rightOperand", Type.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
 
 	/**
-	 * The "patternVariable" structural property of this node type (child type: {@link SingleVariableDeclaration}) (added in JLS14 API).
+	 * The "patternVariable" structural property of this node type (child type: {@link SimpleName}) (added in JLS14 API).
+	 * This contains the name of the instance variable.
 	 * @noreference This property is not intended to be referenced by clients as it is a part of Java preview feature.
 	 * @since 3.22
 	 */
 	public static final ChildPropertyDescriptor PATTERN_VARIABLE_PROPERTY =
-		new ChildPropertyDescriptor(InstanceofExpression.class, "patternVariable", SingleVariableDeclaration.class, OPTIONAL, NO_CYCLE_RISK); //$NON-NLS-1$
+		new ChildPropertyDescriptor(InstanceofExpression.class, "patternVariable", SimpleName.class, OPTIONAL, NO_CYCLE_RISK); //$NON-NLS-1$
 	/**
 	 * A list of property descriptors (element type:
 	 * {@link StructuralPropertyDescriptor}),
@@ -129,7 +130,7 @@
 	/**
 	 * The patternVariable declaration.
 	 */
-	private SingleVariableDeclaration patternVariable = null;
+	private SimpleName patternVariable = null;
 
 	/**
 	 * Creates a new AST node for an instanceof expression owned by the given
@@ -174,7 +175,7 @@
 			if (get) {
 				return getPatternVariable();
 			} else {
-				setPatternVariable((SingleVariableDeclaration) child);
+				setPatternVariable((SimpleName) child);
 				return null;
 			}
 		}
@@ -194,9 +195,9 @@
 		result.setLeftOperand((Expression) getLeftOperand().clone(target));
 		result.setRightOperand((Type) getRightOperand().clone(target));
 		if (DOMASTUtil.isInstanceofExpressionPatternSupported(target)) {
-			SingleVariableDeclaration pv = getPatternVariable();
+			SimpleName pv = getPatternVariable();
 			if (pv != null) {
-				result.setPatternVariable((SingleVariableDeclaration) pv.clone(target));
+				result.setPatternVariable((SimpleName) pv.clone(target));
 			}
 		}
 		return result;
@@ -311,7 +312,7 @@
 	 * @noreference This method is not intended to be referenced by clients as it is a part of Java preview feature.
 	 * @nooverride This method is not intended to be re-implemented or extended by clients as it is a part of Java preview feature.
 	 */
-	public SingleVariableDeclaration getPatternVariable() {
+	public SimpleName getPatternVariable() {
 		supportedOnlyIn15();
 		unsupportedWithoutPreviewError();
 		return this.patternVariable;
@@ -327,7 +328,7 @@
 	 * @noreference This method is not intended to be referenced by clients as it is a part of Java preview feature.
 	 * @nooverride This method is not intended to be re-implemented or extended by clients as it is a part of Java preview feature.
 	 */
-	public void setPatternVariable(SingleVariableDeclaration referencePatternVariable) {
+	public void setPatternVariable(SimpleName referencePatternVariable) {
 		supportedOnlyIn15();
 		unsupportedWithoutPreviewError();
 		if (referencePatternVariable == null) {