diff --git a/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/EndpointServlet.java b/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/EndpointServlet.java
index 1731d6cb8c..44239b2fde 100644
--- a/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/EndpointServlet.java
+++ b/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/EndpointServlet.java
@@ -61,9 +61,9 @@ public final class EndpointServlet {
 
 	public EndpointServlet withInitParameters(Map<String, String> initParameters) {
 		Assert.notNull(initParameters, "InitParameters must not be null");
-		boolean hasEmptyKey = initParameters.values().stream()
-				.anyMatch((key) -> !StringUtils.hasText(key));
-		Assert.isTrue(!hasEmptyKey, "InitParameters must not contain empty keys");
+		boolean hasEmptyName = initParameters.keySet().stream()
+				.anyMatch((name) -> !StringUtils.hasText(name));
+		Assert.isTrue(!hasEmptyName, "InitParameters must not contain empty names");
 		Map<String, String> mergedInitParameters = new LinkedHashMap<>(
 				this.initParameters);
 		mergedInitParameters.putAll(initParameters);
diff --git a/spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/EndpointServletTests.java b/spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/EndpointServletTests.java
index ee26b811fd..77a65d62d0 100644
--- a/spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/EndpointServletTests.java
+++ b/spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/EndpointServletTests.java
@@ -38,6 +38,7 @@ import static org.assertj.core.api.Assertions.entry;
  * Tests for {@link EndpointServlet}.
  *
  * @author Phillip Webb
+ * @author Stephane Nicoll
  */
 public class EndpointServletTests {
 
@@ -71,6 +72,20 @@ public class EndpointServletTests {
 		assertThat(endpointServlet.getServlet()).isEqualTo(servlet);
 	}
 
+	@Test
+	public void withInitParameterNullName() {
+		EndpointServlet endpointServlet = new EndpointServlet(TestServlet.class);
+		this.thrown.expect(IllegalArgumentException.class);
+		endpointServlet.withInitParameters(Collections.singletonMap(null, "value"));
+	}
+
+	@Test
+	public void withInitParameterEmptyName() {
+		EndpointServlet endpointServlet = new EndpointServlet(TestServlet.class);
+		this.thrown.expect(IllegalArgumentException.class);
+		endpointServlet.withInitParameters(Collections.singletonMap(" ", "value"));
+	}
+
 	@Test
 	public void withInitParameterShouldReturnNewInstance() {
 		EndpointServlet endpointServlet = new EndpointServlet(TestServlet.class);