diff --git a/spring-boot/src/main/java/org/springframework/boot/config/YamlProcessor.java b/spring-boot/src/main/java/org/springframework/boot/config/YamlProcessor.java
index a33a18dc9d3..15eb89d5895 100644
--- a/spring-boot/src/main/java/org/springframework/boot/config/YamlProcessor.java
+++ b/spring-boot/src/main/java/org/springframework/boot/config/YamlProcessor.java
@@ -169,13 +169,17 @@ public class YamlProcessor {
 		Map<String, Object> result = new LinkedHashMap<String, Object>();
 		Map<Object, Object> map = (Map<Object, Object>) object;
 		for (Entry<Object, Object> entry : map.entrySet()) {
+			Object value = entry.getValue();
+			if (value instanceof Map) {
+				value = asMap(value);
+			}
 			Object key = entry.getKey();
 			if (key instanceof CharSequence) {
-				result.put(key.toString(), entry.getValue());
+				result.put(key.toString(), value);
 			}
 			else {
 				// It has to be a map key in this case
-				result.put("[" + key.toString() + "]", entry.getValue());
+				result.put("[" + key.toString() + "]", value);
 			}
 		}
 		return result;
diff --git a/spring-boot/src/test/java/org/springframework/boot/config/YamlProcessorTests.java b/spring-boot/src/test/java/org/springframework/boot/config/YamlProcessorTests.java
index 11638fa88ec..ea3570f6b4c 100644
--- a/spring-boot/src/test/java/org/springframework/boot/config/YamlProcessorTests.java
+++ b/spring-boot/src/test/java/org/springframework/boot/config/YamlProcessorTests.java
@@ -76,4 +76,17 @@ public class YamlProcessorTests {
 		});
 	}
 
+	@Test
+	public void integerDeepKeyBehaves() {
+		this.processor.setResources(new Resource[] { new ByteArrayResource(
+				"foo:\n  1: bar".getBytes()) });
+		this.processor.process(new MatchCallback() {
+
+			@Override
+			public void process(Properties properties, Map<String, Object> map) {
+				assertEquals("bar", properties.get("foo[1]"));
+				assertEquals(1, properties.size());
+			}
+		});
+	}
 }