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 790cb2388..5cd9f04eb 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
@@ -275,9 +275,13 @@ public final class CloudEventMessageUtils {
 	 * @return prefix (e.g., 'ce_' or 'ce-' etc.)
 	 */
 	static String determinePrefixToUse(Map<String, Object> messageHeaders) {
+		return determinePrefixToUse(messageHeaders, false);
+	}
+
+	static String determinePrefixToUse(Map<String, Object> messageHeaders, boolean strict) {
 		String targetProtocol = (String) messageHeaders.get(MessageUtils.TARGET_PROTOCOL);
 		String prefix = determinePrefixToUse(targetProtocol);
-		if (StringUtils.hasText(prefix)) {
+		if (StringUtils.hasText(prefix) && (strict || StringUtils.hasText((String) messageHeaders.get(prefix + _SPECVERSION)))) {
 			return prefix;
 		}
 		else {
@@ -294,7 +298,7 @@ public final class CloudEventMessageUtils {
 			}
 		}
 
-		return "";
+		return DEFAULT_ATTR_PREFIX;
 	}
 
 	/**
diff --git a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventsFunctionInvocationHelper.java b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventsFunctionInvocationHelper.java
index 32643c70e..4e29b1c7e 100644
--- a/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventsFunctionInvocationHelper.java
+++ b/spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventsFunctionInvocationHelper.java
@@ -90,7 +90,7 @@ public class CloudEventsFunctionInvocationHelper implements FunctionInvocationHe
 		if (this.messageConverter != null && CLOUD_EVENT_CLASS != null && CLOUD_EVENT_CLASS.isAssignableFrom(result.getClass())) {
 			convertedResult = this.messageConverter.toMessage(result, input.getHeaders());
 		}
-		String targetPrefix = CloudEventMessageUtils.determinePrefixToUse(input.getHeaders());
+		String targetPrefix = CloudEventMessageUtils.determinePrefixToUse(input.getHeaders(), true);
 		return this.doPostProcessResult(convertedResult, targetPrefix);
 	}
 
diff --git a/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/cloudevent/CloudEventMessageUtilsAndBuilderTests.java b/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/cloudevent/CloudEventMessageUtilsAndBuilderTests.java
index 65d298f97..4745e2f2a 100644
--- a/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/cloudevent/CloudEventMessageUtilsAndBuilderTests.java
+++ b/spring-cloud-function-context/src/test/java/org/springframework/cloud/function/cloudevent/CloudEventMessageUtilsAndBuilderTests.java
@@ -31,6 +31,26 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 public class CloudEventMessageUtilsAndBuilderTests {
 
+	@Test// see https://github.com/spring-cloud/spring-cloud-function/issues/680
+	public void testProperAttributeExtractionRegardlessOfTargetProtocol() {
+		Message<String> ceMessage = CloudEventMessageBuilder.withData("foo").build();
+		ceMessage = MessageBuilder.fromMessage(ceMessage).setHeader("target-protocol", "kafka").build();
+
+		String prefix = CloudEventMessageUtils.determinePrefixToUse(ceMessage.getHeaders());
+		assertThat(prefix).isEqualTo("ce-");
+		prefix = CloudEventMessageUtils.determinePrefixToUse(ceMessage.getHeaders(), true);
+		assertThat(prefix).isEqualTo("ce_");
+
+		String specVersion = CloudEventMessageUtils.getSpecVersion(ceMessage);
+		assertThat(specVersion).isEqualTo("1.0");
+		String type = CloudEventMessageUtils.getType(ceMessage);
+		assertThat(type).isEqualTo("java.lang.String");
+		String id = CloudEventMessageUtils.getId(ceMessage);
+		assertThat(id).isNotNull();
+		URI source = CloudEventMessageUtils.getSource(ceMessage);
+		assertThat(source.toString()).isEqualTo("https://spring.io/");
+	}
+
 	@Test
 	public void testAttributeRecognitionAndCanonicalization() {
 		Message<String> httpMessage = MessageBuilder.withPayload("hello")