diff --git a/linter/src/main/java/org/apache/royale/linter/LINTER.java b/linter/src/main/java/org/apache/royale/linter/LINTER.java
index ba4de97..03d6c05 100644
--- a/linter/src/main/java/org/apache/royale/linter/LINTER.java
+++ b/linter/src/main/java/org/apache/royale/linter/LINTER.java
@@ -54,6 +54,7 @@
 import org.apache.royale.linter.rules.ConstantNameRule;
 import org.apache.royale.linter.rules.ConstructorDispatchEventRule;
 import org.apache.royale.linter.rules.ConstructorReturnTypeRule;
+import org.apache.royale.linter.rules.DuplicateObjectKeysRule;
 import org.apache.royale.linter.rules.DynamicClassRule;
 import org.apache.royale.linter.rules.EmptyCommentRule;
 import org.apache.royale.linter.rules.EmptyFunctionBodyRule;
@@ -262,6 +263,9 @@
 			if (configuration.getConstructorDispatchEvent()) {
 				rules.add(new ConstructorDispatchEventRule());
 			}
+			if (configuration.getDuplicateObjectKeys()) {
+				rules.add(new DuplicateObjectKeysRule());
+			}
 			if (configuration.getDynamicClass()) {
 				rules.add(new DynamicClassRule());
 			}
diff --git a/linter/src/main/java/org/apache/royale/linter/config/Configuration.java b/linter/src/main/java/org/apache/royale/linter/config/Configuration.java
index 5d19751..7aac037 100644
--- a/linter/src/main/java/org/apache/royale/linter/config/Configuration.java
+++ b/linter/src/main/java/org/apache/royale/linter/config/Configuration.java
@@ -280,6 +280,22 @@
     }
 
     //
+    // 'duplicate-object-keys' option
+    //
+
+    private boolean duplicateObjectKeys = false;
+
+    public boolean getDuplicateObjectKeys() {
+        return duplicateObjectKeys;
+    }
+
+    @Config
+    @Mapping("duplicate-object-keys")
+    public void setDuplicateObjectKeys(ConfigurationValue cv, boolean b) {
+        this.duplicateObjectKeys = b;
+    }
+
+    //
     // 'constructor-dispatch-event' option
     //
 
diff --git a/linter/src/main/java/org/apache/royale/linter/rules/DuplicateObjectKeysRule.java b/linter/src/main/java/org/apache/royale/linter/rules/DuplicateObjectKeysRule.java
new file mode 100644
index 0000000..d1fef4d
--- /dev/null
+++ b/linter/src/main/java/org/apache/royale/linter/rules/DuplicateObjectKeysRule.java
@@ -0,0 +1,104 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+//  Licensed to the Apache Software Foundation (ASF) under one or more
+//  contributor license agreements.  See the NOTICE file distributed with
+//  this work for additional information regarding copyright ownership.
+//  The ASF licenses this file to You under the Apache License, Version 2.0
+//  (the "License"); you may not use this file except in compliance with
+//  the License.  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////////
+
+package org.apache.royale.linter.rules;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.royale.compiler.internal.tree.as.ContainerNode;
+import org.apache.royale.compiler.problems.CompilerProblem;
+import org.apache.royale.compiler.problems.ICompilerProblem;
+import org.apache.royale.compiler.tree.ASTNodeID;
+import org.apache.royale.compiler.tree.as.IASNode;
+import org.apache.royale.compiler.tree.as.IExpressionNode;
+import org.apache.royale.compiler.tree.as.IIdentifierNode;
+import org.apache.royale.compiler.tree.as.ILiteralContainerNode;
+import org.apache.royale.compiler.tree.as.ILiteralNode;
+import org.apache.royale.compiler.tree.as.ILiteralNode.LiteralType;
+import org.apache.royale.compiler.tree.as.IObjectLiteralValuePairNode;
+import org.apache.royale.linter.LinterRule;
+import org.apache.royale.linter.NodeVisitor;
+import org.apache.royale.linter.TokenQuery;
+
+/**
+ * Check that each key in an object literal is unique.
+ */
+public class DuplicateObjectKeysRule extends LinterRule {
+	@Override
+	public Map<ASTNodeID, NodeVisitor> getNodeVisitors() {
+		Map<ASTNodeID, NodeVisitor> result = new HashMap<>();
+		result.put(ASTNodeID.ObjectLiteralExpressionID, (node, tokenQuery, problems) -> {
+			checkLiteralContainerNode((ILiteralContainerNode) node, tokenQuery, problems);
+		});
+		return result;
+	}
+
+	private void checkLiteralContainerNode(ILiteralContainerNode objectLiteralNode, TokenQuery tokenQuery, Collection<ICompilerProblem> problems) {
+		if (!LiteralType.OBJECT.equals(objectLiteralNode.getLiteralType())) {
+			return;
+		}
+		ContainerNode contentsNode = objectLiteralNode.getContentsNode();
+		if (contentsNode == null) {
+			return;
+		}
+		Set<String> keyNames = new HashSet<>();
+		for (int i = 0; i < contentsNode.getChildCount(); i++) {
+			IASNode child = contentsNode.getChild(i);
+			if (!(child instanceof IObjectLiteralValuePairNode)) {
+				continue;
+			}
+			String keyName = null;
+			IObjectLiteralValuePairNode valuePairNode = (IObjectLiteralValuePairNode) child;
+			IExpressionNode nameNode = valuePairNode.getNameNode();
+			if (nameNode instanceof IIdentifierNode) {
+				IIdentifierNode identifierNode = (IIdentifierNode) nameNode;
+				keyName = identifierNode.getName();
+			} else if (nameNode instanceof ILiteralNode) {
+				ILiteralNode literalNode = (ILiteralNode) nameNode;
+				if (!LiteralType.STRING.equals(literalNode.getLiteralType())) {
+					continue;
+				}
+				keyName = literalNode.getValue();
+			}
+			if (keyName != null) {
+				if (keyNames.contains(keyName)) {
+					problems.add(new DuplicateObjectKeysLinterProblem(nameNode, keyName));
+				} else {
+					keyNames.add(keyName);
+				}
+			}
+		}
+	}
+
+	public static class DuplicateObjectKeysLinterProblem extends CompilerProblem {
+		public static final String DESCRIPTION = "Object literal contains duplicate key '${keyName}'";
+
+		public DuplicateObjectKeysLinterProblem(IExpressionNode node, String keyName)
+		{
+			super(node);
+			this.keyName = keyName;
+		}
+
+		public String keyName;
+	}
+}