diff --git a/spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/flux/FunctionController.java b/spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/flux/FunctionController.java
index 1eb556c26..8328264f0 100644
--- a/spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/flux/FunctionController.java
+++ b/spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/flux/FunctionController.java
@@ -23,7 +23,6 @@ import java.util.function.Supplier;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.cloud.function.context.FunctionInspector;
 import org.springframework.cloud.function.web.flux.request.FluxRequest;
 import org.springframework.http.HttpStatus;
@@ -50,13 +49,16 @@ public class FunctionController {
 
 	private FunctionInspector inspector;
 
-	@Value("${debug:${DEBUG:false}}")
 	private boolean debug = false;
 
 	public FunctionController(FunctionInspector inspector) {
 		this.inspector = inspector;
 	}
 
+	public void setDebug(boolean debug) {
+		this.debug = debug;
+	}
+
 	@PostMapping(path = "/**")
 	@ResponseBody
 	public ResponseEntity<Flux<?>> post(
@@ -65,7 +67,11 @@ public class FunctionController {
 			@RequestAttribute(required = false, name = "org.springframework.cloud.function.web.flux.constants.WebRequestConstants.input_single") Boolean single,
 			@RequestBody FluxRequest<?> body) {
 		if (function != null) {
-			Flux<?> result = (Flux<?>) function.apply(body.flux());
+			Flux<?> flux = body.flux();
+			if (debug) {
+				flux = flux.log();
+			}
+			Flux<?> result = function.apply(flux);
 			if (logger.isDebugEnabled()) {
 				logger.debug("Handled POST with function");
 			}
@@ -73,6 +79,9 @@ public class FunctionController {
 		}
 		if (consumer != null) {
 			Flux<?> flux = body.flux().cache(); // send a copy back to the caller
+			if (debug) {
+				flux = flux.log();
+			}
 			consumer.accept(flux);
 			if (logger.isDebugEnabled()) {
 				logger.debug("Handled POST with consumer");
diff --git a/spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/flux/FunctionHandlerMapping.java b/spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/flux/FunctionHandlerMapping.java
index 6e8a72335..3c9f03edf 100644
--- a/spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/flux/FunctionHandlerMapping.java
+++ b/spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/flux/FunctionHandlerMapping.java
@@ -50,6 +50,9 @@ public class FunctionHandlerMapping extends RequestMappingHandlerMapping
 	@Value("${spring.cloud.function.web.path:}")
 	private String prefix = "";
 
+	@Value("${debug:${DEBUG:false}}")
+	private boolean debug = false;
+
 	@Autowired
 	public FunctionHandlerMapping(FunctionCatalog catalog, FunctionInspector inspector) {
 		this.functions = catalog;
@@ -61,6 +64,7 @@ public class FunctionHandlerMapping extends RequestMappingHandlerMapping
 	@Override
 	public void afterPropertiesSet() {
 		super.afterPropertiesSet();
+		this.controller.setDebug(debug);
 		detectHandlerMethods(controller);
 		while (prefix.endsWith("/")) {
 			prefix = prefix.substring(0, prefix.length() - 1);
diff --git a/spring-cloud-function-web/src/test/java/org/springframework/cloud/function/web/RestApplicationTests.java b/spring-cloud-function-web/src/test/java/org/springframework/cloud/function/web/RestApplicationTests.java
index f5dc2e5bb..44e5a420a 100644
--- a/spring-cloud-function-web/src/test/java/org/springframework/cloud/function/web/RestApplicationTests.java
+++ b/spring-cloud-function-web/src/test/java/org/springframework/cloud/function/web/RestApplicationTests.java
@@ -38,6 +38,7 @@ import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.context.embedded.LocalServerPort;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.context.TestConfiguration;
 import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.context.annotation.Bean;
 import org.springframework.http.HttpStatus;
@@ -65,7 +66,7 @@ public class RestApplicationTests {
 	@Autowired
 	private TestRestTemplate rest;
 	@Autowired
-	private TestConfiguration test;
+	private ApplicationConfiguration test;
 
 	@Before
 	public void init() {
@@ -389,8 +390,8 @@ public class RestApplicationTests {
 	}
 
 	@EnableAutoConfiguration
-	@org.springframework.boot.test.context.TestConfiguration
-	public static class TestConfiguration {
+	@TestConfiguration
+	public static class ApplicationConfiguration {
 
 		private List<String> list = new ArrayList<>();