diff --git a/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyName.java b/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyName.java
index c0f19d972c..a7fa9d8a69 100644
--- a/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyName.java
+++ b/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyName.java
@@ -145,6 +145,9 @@ public final class ConfigurationPropertyName
 	 * @return {@code true} if this name is an ancestor
 	 */
 	public boolean isAncestorOf(ConfigurationPropertyName name) {
+		if (this.equals(EMPTY)) {
+			return true;
+		}
 		ConfigurationPropertyName candidate = (name == null ? null : name.getParent());
 		while (candidate != null) {
 			if (candidate.equals(this)) {
diff --git a/spring-boot/src/test/java/org/springframework/boot/context/properties/source/ConfigurationPropertyNameTests.java b/spring-boot/src/test/java/org/springframework/boot/context/properties/source/ConfigurationPropertyNameTests.java
index a0df87b141..695995515a 100644
--- a/spring-boot/src/test/java/org/springframework/boot/context/properties/source/ConfigurationPropertyNameTests.java
+++ b/spring-boot/src/test/java/org/springframework/boot/context/properties/source/ConfigurationPropertyNameTests.java
@@ -274,6 +274,15 @@ public class ConfigurationPropertyNameTests {
 		assertThat(grandchild.isAncestorOf(parent)).isFalse();
 	}
 
+	@Test
+	public void isAncestorOfWhenRootReturnTrue() throws Exception {
+		ConfigurationPropertyName parent = ConfigurationPropertyName.of("");
+		ConfigurationPropertyName grandchild = ConfigurationPropertyName
+				.of("foo.bar.baz");
+		assertThat(parent.isAncestorOf(grandchild)).isTrue();
+		assertThat(grandchild.isAncestorOf(parent)).isFalse();
+	}
+
 	@Test
 	public void appendWhenNotIndexedShouldAppendWithDot() throws Exception {
 		ConfigurationPropertyName name = ConfigurationPropertyName.of("foo");