diff --git a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java
index 40414c871..d90d92ee5 100644
--- a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java
+++ b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/SimpleFunctionRegistry.java
@@ -815,6 +815,9 @@ public class SimpleFunctionRegistry implements FunctionRegistry, FunctionInspect
 		 */
 		@SuppressWarnings("unchecked")
 		private Object fluxifyInputIfNecessary(Object input) {
+			if (input instanceof Message && !((Message) input).getHeaders().containsKey("user-agent") && this.isConsumer() && !this.isInputTypePublisher()) {
+				return input;
+			}
 			if (FunctionTypeUtils.isMultipleArgumentType(this.inputType)) {
 				return input;
 			}