diff --git a/spring-integration-core/src/main/java/org/springframework/integration/dsl/RecipientListRouterSpec.java b/spring-integration-core/src/main/java/org/springframework/integration/dsl/RecipientListRouterSpec.java
index c217e4b239..222867317f 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/dsl/RecipientListRouterSpec.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/dsl/RecipientListRouterSpec.java
@@ -102,9 +102,10 @@ public class RecipientListRouterSpec extends AbstractRouterSpec<RecipientListRou
 			messageSelector = (MessageSelector) selector;
 		}
 		else {
-			messageSelector = isLambda(selector)
-					? new MethodInvokingSelector(new LambdaMessageProcessor(selector, null))
-					: new MethodInvokingSelector(selector);
+			messageSelector =
+					isLambda(selector)
+							? new MethodInvokingSelector(new LambdaMessageProcessor(selector, null))
+							: new MethodInvokingSelector(selector);
 		}
 		this.target.addRecipient(channelName, messageSelector);
 		return _this();
@@ -170,7 +171,10 @@ public class RecipientListRouterSpec extends AbstractRouterSpec<RecipientListRou
 			messageSelector = (MessageSelector) selector;
 		}
 		else {
-			messageSelector = new MethodInvokingSelector(new LambdaMessageProcessor(selector, null));
+			messageSelector =
+					isLambda(selector)
+							? new MethodInvokingSelector(new LambdaMessageProcessor(selector, null))
+							: new MethodInvokingSelector(selector);
 		}
 		this.target.addRecipient(channel, messageSelector);
 		return _this();
diff --git a/spring-integration-core/src/main/java/org/springframework/integration/handler/LambdaMessageProcessor.java b/spring-integration-core/src/main/java/org/springframework/integration/handler/LambdaMessageProcessor.java
index ab61377780..e5914fdd73 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/handler/LambdaMessageProcessor.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/handler/LambdaMessageProcessor.java
@@ -60,18 +60,23 @@ public class LambdaMessageProcessor implements MessageProcessor<Object>, BeanFac
 		final AtomicReference<Method> methodValue = new AtomicReference<>();
 		ReflectionUtils.doWithMethods(target.getClass(),
 				methodValue::set,
-				methodCandidate ->
-						!methodCandidate.isBridge()
-								&& !methodCandidate.isDefault()
-								&& methodCandidate.getDeclaringClass() != Object.class
-								&& Modifier.isPublic(methodCandidate.getModifiers())
-								&& !Modifier.isStatic(methodCandidate.getModifiers()));
+				methodCandidate -> {
+					boolean isCandidate = !methodCandidate.isBridge()
+							&& !methodCandidate.isDefault()
+							&& methodCandidate.getDeclaringClass() != Object.class
+							&& Modifier.isPublic(methodCandidate.getModifiers())
+							&& !Modifier.isStatic(methodCandidate.getModifiers());
+					if (isCandidate) {
+						Assert.isNull(methodValue.get(), "LambdaMessageProcessor is applicable for inline or lambda " +
+								"classes with single method - functional interface implementations.");
+					}
+					return isCandidate;
+				});
 
 		Assert.notNull(methodValue.get(), "LambdaMessageProcessor is applicable for inline or lambda " +
 				"classes with single method - functional interface implementations.");
 
 		this.method = methodValue.get();
-		this.method.setAccessible(true);
 		this.parameterTypes = this.method.getParameterTypes();
 		this.payloadType = payloadType != null ? TypeDescriptor.valueOf(payloadType) : null;
 	}