diff --git a/pom.xml b/pom.xml
index 7aeabee1f..494cffc2b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,7 +4,6 @@
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>spring-cloud-stream-parent</artifactId>
-	<version>4.0.0-SNAPSHOT</version>
 	<packaging>pom</packaging>
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
@@ -25,7 +24,7 @@
 		<java.version>17</java.version>
 		<reactor.version>2020.0.7</reactor.version>
 		<objenesis.version>2.1</objenesis.version>
-		<spring-cloud-function.version>3.2.2-SNAPSHOT</spring-cloud-function.version>
+		<spring-cloud-function.version>4.0.0-SNAPSHOT</spring-cloud-function.version>
 		<maven-checkstyle-plugin.failsOnError>true</maven-checkstyle-plugin.failsOnError>
 		<maven-checkstyle-plugin.failsOnViolation>true</maven-checkstyle-plugin.failsOnViolation>
 		<maven-checkstyle-plugin.includeTestSourceDirectory>true</maven-checkstyle-plugin.includeTestSourceDirectory>
diff --git a/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/FunctionConfiguration.java b/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/FunctionConfiguration.java
index e5205d9a3..ae87ef2f1 100644
--- a/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/FunctionConfiguration.java
+++ b/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/FunctionConfiguration.java
@@ -58,7 +58,6 @@ import org.springframework.cloud.function.context.FunctionCatalog;
 import org.springframework.cloud.function.context.FunctionProperties;
 import org.springframework.cloud.function.context.FunctionRegistry;
 import org.springframework.cloud.function.context.PollableBean;
-import org.springframework.cloud.function.context.catalog.FunctionInspector;
 import org.springframework.cloud.function.context.catalog.FunctionTypeUtils;
 import org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry.FunctionInvocationWrapper;
 import org.springframework.cloud.function.context.config.ContextFunctionCatalogAutoConfiguration;
@@ -939,7 +938,10 @@ public class FunctionConfiguration {
 				streamFunctionProperties.setDefinition(RoutingFunction.FUNCTION_NAME);
 			}
 			else if (autodetect) {
-				streamFunctionProperties.setDefinition(((FunctionInspector) functionCatalog).getName(functionCatalog.lookup("")));
+				FunctionInvocationWrapper function = functionCatalog.lookup("");
+				if (function != null) {
+					streamFunctionProperties.setDefinition(function.getFunctionDefinition());
+				}
 			}
 			return StringUtils.hasText(streamFunctionProperties.getDefinition());
 		}
diff --git a/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/StreamBridge.java b/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/StreamBridge.java
index 2d259e07b..2c2dbeecd 100644
--- a/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/StreamBridge.java
+++ b/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/StreamBridge.java
@@ -16,6 +16,7 @@
 
 package org.springframework.cloud.stream.function;
 
+import java.lang.reflect.Type;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -29,7 +30,6 @@ import org.springframework.beans.factory.SmartInitializingSingleton;
 import org.springframework.cloud.function.context.FunctionCatalog;
 import org.springframework.cloud.function.context.FunctionRegistration;
 import org.springframework.cloud.function.context.FunctionRegistry;
-import org.springframework.cloud.function.context.FunctionType;
 import org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry.FunctionInvocationWrapper;
 import org.springframework.cloud.function.context.message.MessageUtils;
 import org.springframework.cloud.stream.binder.Binder;
@@ -42,6 +42,7 @@ import org.springframework.cloud.stream.config.BindingProperties;
 import org.springframework.cloud.stream.config.BindingServiceProperties;
 import org.springframework.cloud.stream.messaging.DirectWithAttributesChannel;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.core.ResolvableType;
 import org.springframework.integration.channel.AbstractMessageChannel;
 import org.springframework.integration.config.GlobalChannelInterceptorProcessor;
 import org.springframework.integration.support.MessageBuilder;
@@ -241,7 +242,8 @@ public final class StreamBridge implements SmartInitializingSingleton {
 		}
 		FunctionRegistration<Function<Object, Object>> fr = new FunctionRegistration<>(v -> v, STREAM_BRIDGE_FUNC_NAME);
 		fr.getProperties().put("singleton", "false");
-		this.functionRegistry.register(fr.type(FunctionType.from(Object.class).to(Object.class).message()));
+		Type functionType = ResolvableType.forClassWithGenerics(Function.class, Object.class, Object.class).getType();
+		this.functionRegistry.register(fr.type(functionType));
 		Map<String, DirectWithAttributesChannel> channels = applicationContext.getBeansOfType(DirectWithAttributesChannel.class);
 		for (Entry<String, DirectWithAttributesChannel> channelEntry : channels.entrySet()) {
 			if (channelEntry.getValue().getAttribute("type").equals("output")) {
diff --git a/spring-cloud-stream/src/test/java/org/springframework/cloud/stream/function/ImplicitFunctionBindingTests.java b/spring-cloud-stream/src/test/java/org/springframework/cloud/stream/function/ImplicitFunctionBindingTests.java
index 7f225cc57..4e1e5f015 100644
--- a/spring-cloud-stream/src/test/java/org/springframework/cloud/stream/function/ImplicitFunctionBindingTests.java
+++ b/spring-cloud-stream/src/test/java/org/springframework/cloud/stream/function/ImplicitFunctionBindingTests.java
@@ -41,7 +41,6 @@ import org.springframework.boot.WebApplicationType;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.cloud.function.context.FunctionRegistration;
-import org.springframework.cloud.function.context.FunctionType;
 import org.springframework.cloud.function.context.catalog.FunctionAroundWrapper;
 import org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry.FunctionInvocationWrapper;
 import org.springframework.cloud.function.context.config.ContextFunctionCatalogAutoConfiguration;
@@ -57,6 +56,7 @@ import org.springframework.cloud.stream.messaging.DirectWithAttributesChannel;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
+import org.springframework.core.ResolvableType;
 import org.springframework.integration.channel.QueueChannel;
 import org.springframework.integration.dsl.IntegrationFlow;
 import org.springframework.integration.dsl.IntegrationFlows;
@@ -157,7 +157,7 @@ public class ImplicitFunctionBindingTests {
 
 			Function<byte[], byte[]> function = v -> v;
 			FunctionRegistration functionRegistration = new FunctionRegistration(function, "function");
-			functionRegistration = functionRegistration.type(FunctionType.from(byte[].class).to(byte[].class));
+			functionRegistration = functionRegistration.type(ResolvableType.forClassWithGenerics(Function.class, Object.class, Object.class).getType());
 			FunctionBindingTestUtils.bind(context, functionRegistration);
 
 			input.send(new GenericMessage<byte[]>("hello".getBytes()), "input");