diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/CollectionBinder.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/CollectionBinder.java
index cfd887dde2..618c80d034 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/CollectionBinder.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/CollectionBinder.java
@@ -57,7 +57,7 @@ class CollectionBinder extends IndexedElementsBinder<Collection<Object>> {
 	@Override
 	protected Collection<Object> merge(Supplier<Collection<Object>> existing,
 			Collection<Object> additional) {
-		Collection<Object> existingCollection = existing.get();
+		Collection<Object> existingCollection = getExistingIfPossible(existing);
 		if (existingCollection == null) {
 			return additional;
 		}
@@ -71,6 +71,15 @@ class CollectionBinder extends IndexedElementsBinder<Collection<Object>> {
 		}
 	}
 
+	private Collection<Object> getExistingIfPossible(Supplier<Collection<Object>> existing) {
+		try {
+			return existing.get();
+		}
+		catch (Exception ex) {
+			return null;
+		}
+	}
+
 	private Collection<Object> copyIfPossible(Collection<Object> collection) {
 		try {
 			return createNewCollection(collection);
diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/MapBinder.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/MapBinder.java
index 01939e7666..29ceb2f253 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/MapBinder.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/MapBinder.java
@@ -85,26 +85,45 @@ class MapBinder extends AggregateBinder<Map<Object, Object>> {
 	@Override
 	protected Map<Object, Object> merge(Supplier<Map<Object, Object>> existing,
 			Map<Object, Object> additional) {
-		Map<Object, Object> existingMap = existing.get();
+		Map<Object, Object> existingMap = getExistingIfPossible(existing);
 		if (existingMap == null) {
 			return additional;
 		}
-		existingMap.putAll(additional);
-		return copyIfPossible(existingMap);
+		try {
+			existingMap.putAll(additional);
+			return copyIfPossible(existingMap);
+		}
+		catch (UnsupportedOperationException ex) {
+			Map<Object, Object> result = createNewMap(additional.getClass(), existingMap);
+			result.putAll(additional);
+			return result;
+		}
+	}
+
+	private Map<Object, Object> getExistingIfPossible(Supplier<Map<Object, Object>> existing) {
+		try {
+			return existing.get();
+		}
+		catch (Exception ex) {
+			return null;
+		}
 	}
 
 	private Map<Object, Object> copyIfPossible(Map<Object, Object> map) {
 		try {
-			Map<Object, Object> result = CollectionFactory.createMap(map.getClass(),
-					map.size());
-			result.putAll(map);
-			return result;
+			return createNewMap(map.getClass(), map);
 		}
 		catch (Exception ex) {
 			return map;
 		}
 	}
 
+	private Map<Object, Object> createNewMap(Class<?> mapClass, Map<Object, Object> map) {
+		Map<Object, Object> result = CollectionFactory.createMap(mapClass, map.size());
+		result.putAll(map);
+		return result;
+	}
+
 	private class EntryBinder {
 
 		private final ConfigurationPropertyName root;
diff --git a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/CollectionBinderTests.java b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/CollectionBinderTests.java
index 25dade2c2b..cd057173ef 100644
--- a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/CollectionBinderTests.java
+++ b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/CollectionBinderTests.java
@@ -417,6 +417,16 @@ public class CollectionBinderTests {
 		assertThat(bean.getBar()).containsExactly("hello");
 	}
 
+	@Test
+	public void bindToBeanWithExceptionInGetterForExistingValue() {
+		MockConfigurationPropertySource source = new MockConfigurationPropertySource();
+		source.put("foo.values", "a,b,c");
+		this.sources.add(source);
+		BeanWithGetterException result = this.binder
+				.bind("foo", Bindable.of(BeanWithGetterException.class)).get();
+		assertThat(result.getValues()).containsExactly("a", "b", "c");
+	}
+
 	public static class ExampleCollectionBean {
 
 		private List<String> items = new ArrayList<>();
@@ -521,4 +531,18 @@ public class CollectionBinderTests {
 
 	}
 
+	public static class BeanWithGetterException {
+
+		private List<String> values;
+
+		public void setValues(List<String> values) {
+			this.values = values;
+		}
+
+		public List<String> getValues() {
+			return Collections.unmodifiableList(this.values);
+		}
+
+	}
+
 }
diff --git a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/MapBinderTests.java b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/MapBinderTests.java
index 5920a31b3d..6e9607777f 100644
--- a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/MapBinderTests.java
+++ b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/MapBinderTests.java
@@ -615,6 +615,32 @@ public class MapBinderTests {
 		assertThat(result.getItems()).containsExactly(entry("a", "b"));
 	}
 
+	@Test
+	public void bindToImmutableMapShouldReturnPopulatedCollection() {
+		MockConfigurationPropertySource source = new MockConfigurationPropertySource();
+		source.put("foo.values.c", "d");
+		source.put("foo.values.e", "f");
+		this.sources.add(source);
+		Map<String, String> result = this.binder
+				.bind("foo.values",
+						STRING_STRING_MAP
+								.withExistingValue(Collections.singletonMap("a", "b")))
+				.get();
+		assertThat(result).hasSize(3);
+		assertThat(result.entrySet()).containsExactly(entry("a", "b"), entry("c", "d"),
+				entry("e", "f"));
+	}
+
+	@Test
+	public void bindToBeanWithExceptionInGetterForExistingValue() {
+		MockConfigurationPropertySource source = new MockConfigurationPropertySource();
+		source.put("foo.values.a", "b");
+		this.sources.add(source);
+		BeanWithGetterException result = this.binder
+				.bind("foo", Bindable.of(BeanWithGetterException.class)).get();
+		assertThat(result.getValues()).containsExactly(entry("a", "b"));
+	}
+
 	private <K, V> Bindable<Map<K, V>> getMapBindable(Class<K> keyGeneric,
 			ResolvableType valueType) {
 		ResolvableType keyType = ResolvableType.forClass(keyGeneric);
@@ -720,4 +746,18 @@ public class MapBinderTests {
 
 	}
 
+	public static class BeanWithGetterException {
+
+		private Map<String, String> values;
+
+		public void setValues(Map<String, String> values) {
+			this.values = values;
+		}
+
+		public Map<String, String> getValues() {
+			return Collections.unmodifiableMap(this.values);
+		}
+
+	}
+
 }