diff --git a/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binding/MessageConverterConfigurer.java b/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binding/MessageConverterConfigurer.java
index 8c839c72c..dd7e4439f 100644
--- a/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binding/MessageConverterConfigurer.java
+++ b/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/binding/MessageConverterConfigurer.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2020 the original author or authors.
+ * Copyright 2015-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,6 +35,7 @@ import org.springframework.cloud.stream.binder.ProducerProperties;
 import org.springframework.cloud.stream.config.BindingProperties;
 import org.springframework.cloud.stream.config.BindingServiceProperties;
 import org.springframework.cloud.stream.converter.MessageConverterUtils;
+import org.springframework.cloud.stream.function.BindableFunctionProxyFactory;
 import org.springframework.cloud.stream.function.StreamFunctionProperties;
 import org.springframework.core.env.Environment;
 import org.springframework.integration.channel.AbstractMessageChannel;
@@ -164,7 +165,9 @@ public class MessageConverterConfigurer
 			}
 			else {
 				if (environment != null && environment.containsProperty("spring.cloud.stream.rabbit.bindings." + channelName + ".producer.routing-key-expression")) {
-					this.setSkipOutputConversionIfNecessary();
+					Map<String, String> channelNameToFunctions = BindableFunctionProxyFactory.getChannelNameToFunctions();
+					String functionName = channelNameToFunctions.get(channelName);
+					this.setSkipOutputConversionIfNecessary(functionName);
 					functional = false;
 				}
 				if (!functional) {
@@ -174,10 +177,10 @@ public class MessageConverterConfigurer
 		}
 	}
 
-	private void setSkipOutputConversionIfNecessary() {
+	private void setSkipOutputConversionIfNecessary(String functionName) {
 		FunctionCatalog catalog = this.beanFactory.getBean(FunctionCatalog.class);
 		if (catalog != null) {
-			FunctionInvocationWrapper function = catalog.lookup(this.streamFunctionProperties.getDefinition());
+			FunctionInvocationWrapper function = catalog.lookup(functionName);
 			if (function != null) {
 				function.setSkipOutputConversion(true);
 			}
diff --git a/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/BindableFunctionProxyFactory.java b/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/BindableFunctionProxyFactory.java
index 28efc5ed0..153356ead 100644
--- a/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/BindableFunctionProxyFactory.java
+++ b/core/spring-cloud-stream/src/main/java/org/springframework/cloud/stream/function/BindableFunctionProxyFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2021 the original author or authors.
+ * Copyright 2019-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,9 @@
 
 package org.springframework.cloud.stream.function;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.FactoryBean;
 import org.springframework.cloud.stream.binder.PollableMessageSource;
@@ -62,6 +65,14 @@ public class BindableFunctionProxyFactory extends BindableProxyFactory implement
 
 	private GenericApplicationContext context;
 
+	/**
+	 * A convenient table containing the channel-name to function-name relationship.
+	 * This will be accessed via a utility method later on during the binding phase.
+	 * It is provided to assist with identifying the correct function that a channel
+	 * binds to when there are multiple functions present in the function definition.
+	 */
+	private static Map<String, String> channelNameToFunctions = new HashMap<>();
+
 	public BindableFunctionProxyFactory(String functionDefinition, int inputCount, int outputCount, StreamFunctionProperties functionProperties) {
 		this(functionDefinition, inputCount, outputCount, functionProperties, new SupportedBindableFeatures(), true);
 	}
@@ -166,6 +177,7 @@ public class BindableFunctionProxyFactory extends BindableProxyFactory implement
 		if (this.functionProperties.getBindings().containsKey(name)) {
 			name = this.functionProperties.getBindings().get(name);
 		}
+		updateChannelNameToFunctionName(name);
 		if (this.supportedBindableFeatures.isPollable()) {
 			PollableMessageSource pollableSource = (PollableMessageSource) getBindingTargetFactory(PollableMessageSource.class).createInput(name);
 			if (context != null && !context.containsBean(name)) {
@@ -185,10 +197,18 @@ public class BindableFunctionProxyFactory extends BindableProxyFactory implement
 		}
 	}
 
+	private void updateChannelNameToFunctionName(String name) {
+		// Update the channelName -> functionName table. Even if the application provides
+		// multiple functions in the function definition configuration (function1;function2;function3 etc.),
+		// this proxy factory only knows about a single function.
+		channelNameToFunctions.put(name, this.functionDefinition);
+	}
+
 	private void createOutput(String name) {
 		if (this.functionProperties.getBindings().containsKey(name)) {
 			name = this.functionProperties.getBindings().get(name);
 		}
+		updateChannelNameToFunctionName(name);
 		if (this.supportedBindableFeatures.isReactive()) {
 			this.outputHolders.put(name,
 				new BoundTargetHolder(getBindingTargetFactory(FluxMessageChannel.class)
@@ -209,4 +229,8 @@ public class BindableFunctionProxyFactory extends BindableProxyFactory implement
 	public boolean isFunctionExist() {
 		return functionExist;
 	}
+
+	public static Map<String, String> getChannelNameToFunctions() {
+		return channelNameToFunctions;
+	}
 }