diff --git a/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/environment/EnvironmentController.java b/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/environment/EnvironmentController.java
index f54662a4..b01b1b52 100644
--- a/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/environment/EnvironmentController.java
+++ b/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/environment/EnvironmentController.java
@@ -481,6 +481,7 @@ public class EnvironmentController {
 		private String getKey() {
 			// Consider initial value or previous char '.' or '['
 			int start = this.currentPos + 1;
+			int openingBracketPosition = -1;
 			for (int i = start; i < this.propertyKey.length(); i++) {
 				char currentChar = this.propertyKey.charAt(i);
 				if (currentChar == '.') {
@@ -489,9 +490,20 @@ public class EnvironmentController {
 					break;
 				}
 				else if (currentChar == '[') {
-					this.valueType = NodeType.ARRAY;
-					this.currentPos = i;
-					break;
+					openingBracketPosition = i;
+				}
+				else if (currentChar == ']') {
+					String bracketContents = this.propertyKey.substring(openingBracketPosition + 1, i);
+					try {
+						Integer.parseInt(bracketContents);
+						this.valueType = NodeType.ARRAY;
+						this.currentPos = openingBracketPosition;
+						break;
+					}
+					catch (NumberFormatException e) {
+						// This means the key contains a [ and a ] but the contents were
+						// not an integer so it's not an array
+					}
 				}
 			}
 			// If there's no delimiter then it's a key of a leaf
diff --git a/spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/environment/EnvironmentControllerTests.java b/spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/environment/EnvironmentControllerTests.java
index ccf15c84..415a33bd 100644
--- a/spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/environment/EnvironmentControllerTests.java
+++ b/spring-cloud-config-server/src/test/java/org/springframework/cloud/config/server/environment/EnvironmentControllerTests.java
@@ -182,6 +182,19 @@ class EnvironmentControllerTests {
 		assertThat(yaml).isEqualTo("a:\n  b:\n  - c\n  - d\n");
 	}
 
+	@Test
+	public void yamlWithBrackets() throws Exception {
+		Map<String, Object> map = new LinkedHashMap<String, Object>();
+		map.put("a.test", "e");
+		map.put("a.b[hello]", "c");
+		map.put("a.b[world]", "d");
+		map.put("a.b[world]d", "f");
+		this.environment.add(new PropertySource("one", map));
+		when(this.repository.findOne("foo", "bar", null, false)).thenReturn(this.environment);
+		String yaml = this.controller.yaml("foo", "bar", false).getBody();
+		assertThat(yaml).isEqualTo("a:\n  test: e\n  b[hello]: c\n  b[world]: d\n  b[world]d: f\n");
+	}
+
 	@Test
 	public void arrayOverridenInEnvironment() throws Exception {
 		// Add original values first source