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 2f66d6236..40414c871 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
@@ -927,7 +927,11 @@ public class SimpleFunctionRegistry implements FunctionRegistry, FunctionInspect
 			if (inputValue instanceof Message && !this.isInputTypeMessage()) {
 				inputValue = ((Message) inputValue).getPayload();
 			}
-			System.out.println("Invoking function: " + this + "with input type: " + this.getInputType());
+
+			if (logger.isDebugEnabled()) {
+				logger.debug("Invoking function: " + this + "with input type: " + this.getInputType());
+			}
+
 			Object result = ((Function) this.target).apply(inputValue);
 
 			if (result instanceof Publisher && functionInvocationHelper != null) {