diff --git a/spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/main/groovy/org/springframework/cloud/contract/verifier/plugin/ExtensionToProperties.groovy b/spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/main/groovy/org/springframework/cloud/contract/verifier/plugin/ExtensionToProperties.groovy
index ae8538d39a..ccfaead290 100644
--- a/spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/main/groovy/org/springframework/cloud/contract/verifier/plugin/ExtensionToProperties.groovy
+++ b/spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/main/groovy/org/springframework/cloud/contract/verifier/plugin/ExtensionToProperties.groovy
@@ -13,24 +13,24 @@ class ExtensionToProperties {
 
 	protected static ContractVerifierConfigProperties fromExtension(ContractVerifierExtension extension) {
 		return new ContractVerifierConfigProperties(
-				targetFramework: extension.testFramework,
-				testMode: extension.testMode,
-				basePackageForTests: extension.basePackageForTests,
-				baseClassForTests: extension.baseClassForTests,
-				nameSuffixForTests: extension.nameSuffixForTests,
-				ruleClassForTests: extension.ruleClassForTests,
-				excludedFiles: extension.excludedFiles,
-				ignoredFiles: extension.ignoredFiles,
-				imports: extension.imports,
-				staticImports: extension.staticImports,
-				contractsDslDir: extension.contractsDslDir,
-				generatedTestSourcesDir: extension.generatedTestSourcesDir,
-				stubsOutputDir: extension.stubsOutputDir,
-				stubsSuffix: extension.stubsSuffix,
-				assertJsonSize: extension.assertJsonSize,
-				packageWithBaseClasses: extension.packageWithBaseClasses,
-				baseClassMappings: extension.baseClassMappings,
-				excludeBuildFolders: extension.excludeBuildFolders
+				targetFramework: extension.getTestFramework(),
+				testMode: extension.getTestMode(),
+				basePackageForTests: extension.getBasePackageForTests(),
+				baseClassForTests: extension.getBaseClassForTests(),
+				nameSuffixForTests: extension.getNameSuffixForTests(),
+				ruleClassForTests: extension.getRuleClassForTests(),
+				excludedFiles: extension.getExcludedFiles(),
+				ignoredFiles: extension.getIgnoredFiles(),
+				imports: extension.getImports(),
+				staticImports: extension.getStaticImports(),
+				contractsDslDir: extension.getContractsDslDir(),
+				generatedTestSourcesDir: extension.getGeneratedTestSourcesDir(),
+				stubsOutputDir: extension.getStubsOutputDir(),
+				stubsSuffix: extension.getStubsSuffix(),
+				assertJsonSize: extension.getAssertJsonSize(),
+				packageWithBaseClasses: extension.getPackageWithBaseClasses(),
+				baseClassMappings: extension.getBaseClassMappings(),
+				excludeBuildFolders: extension.getExcludeBuildFolders()
 		)
 	}
 }
diff --git a/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/messaging/amqp/SpringAmqpStubMessages.java b/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/messaging/amqp/SpringAmqpStubMessages.java
index 6e61e39a09..7ac0767ebe 100644
--- a/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/messaging/amqp/SpringAmqpStubMessages.java
+++ b/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/messaging/amqp/SpringAmqpStubMessages.java
@@ -86,21 +86,36 @@ public class SpringAmqpStubMessages implements MessageVerifier<Message> {
 	public <T> void send(T payload, Map<String, Object> headers, String destination) {
 		Message message = org.springframework.amqp.core.MessageBuilder
 				.withBody(((String) payload).getBytes())
-				.andProperties(MessagePropertiesBuilder.newInstance()
-						.setContentType((String) headers.get("contentType"))
-						.copyHeaders(headers).build())
+				.andProperties(
+						MessagePropertiesBuilder.newInstance()
+								.setContentType(header(headers, "contentType"))
+								.copyHeaders(headers).build())
 				.build();
 		if (headers != null && headers.containsKey(DEFAULT_CLASSID_FIELD_NAME)) {
 			message.getMessageProperties().setHeader(DEFAULT_CLASSID_FIELD_NAME,
 					headers.get(DEFAULT_CLASSID_FIELD_NAME));
 		}
 		if (headers != null && headers.containsKey(AmqpHeaders.RECEIVED_ROUTING_KEY)) {
-			message.getMessageProperties().setReceivedRoutingKey(
-					(String) headers.get(AmqpHeaders.RECEIVED_ROUTING_KEY));
+			message.getMessageProperties()
+					.setReceivedRoutingKey(header(headers, AmqpHeaders.RECEIVED_ROUTING_KEY));
 		}
 		send(message, destination);
 	}
 
+	private String header(Map<String, Object> headers, String headerName) {
+		if (headers == null) {
+			return "";
+		}
+		Object value = headers.get(headerName);
+		if (value instanceof String) {
+			return (String) value;
+		} else if (value instanceof Iterable) {
+			Iterable values = ((Iterable) value);
+			return values.iterator().hasNext() ? (String) values.iterator().next() : "";
+		}
+		return value.toString();
+	}
+
 	@Override
 	public void send(Message message, String destination) {
 		final String routingKey = message.getMessageProperties().getReceivedRoutingKey();