diff --git a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventMessageUtils.java b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventMessageUtils.java
index 55ab9a49a..552ce4f12 100644
--- a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventMessageUtils.java
+++ b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventMessageUtils.java
@@ -32,6 +32,7 @@ import org.springframework.messaging.converter.ContentTypeResolver;
 import org.springframework.messaging.converter.DefaultContentTypeResolver;
 import org.springframework.messaging.converter.MessageConverter;
 import org.springframework.messaging.support.MessageBuilder;
+import org.springframework.util.Assert;
 import org.springframework.util.MimeType;
 import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.StringUtils;
@@ -228,15 +229,16 @@ public final class CloudEventMessageUtils {
 	static Message<?> toCanonical(Message<?> inputMessage, MessageConverter messageConverter) {
 		Map<String, Object> headers = new HashMap<>(inputMessage.getHeaders());
 		canonicalizeHeaders(headers, false);
-		if (isCloudEvent(inputMessage) && headers.containsKey("content-type")) {
+		boolean isCloudEvent = isCloudEvent(inputMessage);
+		if (isCloudEvent && headers.containsKey("content-type")) {
 			inputMessage = MessageBuilder.fromMessage(inputMessage).setHeader(MessageHeaders.CONTENT_TYPE, headers.get("content-type")).build();
 		}
 
 		String inputContentType = (String) inputMessage.getHeaders().get(DATACONTENTTYPE);
+		MimeType contentType = contentTypeResolver.resolve(inputMessage.getHeaders());
 		// first check the obvious and see if content-type is `cloudevents`
-		if (!isCloudEvent(inputMessage) && headers.containsKey(MessageHeaders.CONTENT_TYPE)) {
+		if (!isCloudEvent && contentType != null) {
 			// structured-mode
-			MimeType contentType = contentTypeResolver.resolve(inputMessage.getHeaders());
 			if (contentType.getType().equals(APPLICATION_CLOUDEVENTS.getType()) && contentType
 					.getSubtype().startsWith(APPLICATION_CLOUDEVENTS.getSubtype())) {
 
@@ -251,7 +253,7 @@ public final class CloudEventMessageUtils {
 						.setHeader(DATACONTENTTYPE, dataContentType).build();
 				Map<String, Object> structuredCloudEvent = (Map<String, Object>) messageConverter
 						.fromMessage(cloudEventMessage, Map.class);
-
+				Assert.notEmpty(structuredCloudEvent, "Failed to convert CloudEvent from structured mode");
 				canonicalizeHeaders(structuredCloudEvent, true);
 				return buildBinaryMessageFromStructuredMap(structuredCloudEvent,
 						inputMessage.getHeaders());
diff --git a/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/cloudevent/CloudEventFunctionTests.java b/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/cloudevent/CloudEventFunctionTests.java
index 388b0f057..0ad602b4e 100644
--- a/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/cloudevent/CloudEventFunctionTests.java
+++ b/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/cloudevent/CloudEventFunctionTests.java
@@ -391,6 +391,7 @@ public class CloudEventFunctionTests {
 		Function<Message<SpringReleaseEvent>, Message<SpringReleaseEvent>> springReleaseAsMessage() {
 			return message -> {
 				SpringReleaseEvent updated = springRelease().apply(message.getPayload());
+				assertThat(message.getHeaders().get("ce-type")).isEqualTo("org.springframework");
 				return CloudEventMessageBuilder.withData(updated)
 						.copyHeaders(message.getHeaders())
 						.setSource("https://spring.release.event")