diff --git a/src/main/java/org/springframework/hateoas/UriTemplate.java b/src/main/java/org/springframework/hateoas/UriTemplate.java
index 1d6bfa34..c0bfc809 100644
--- a/src/main/java/org/springframework/hateoas/UriTemplate.java
+++ b/src/main/java/org/springframework/hateoas/UriTemplate.java
@@ -179,7 +179,7 @@ public class UriTemplate implements Iterable<TemplateVariable> {
 	 * @param parameters must not be {@literal null}.
 	 * @return
 	 */
-	public URI expand(Map<String, Object> parameters) {
+	public URI expand(Map<String, ? extends Object> parameters) {
 
 		if (TemplateVariables.NONE.equals(variables)) {
 			return URI.create(baseUri);
diff --git a/src/test/java/org/springframework/hateoas/UriTemplateUnitTest.java b/src/test/java/org/springframework/hateoas/UriTemplateUnitTest.java
index b7d84863..d243c2c7 100644
--- a/src/test/java/org/springframework/hateoas/UriTemplateUnitTest.java
+++ b/src/test/java/org/springframework/hateoas/UriTemplateUnitTest.java
@@ -124,7 +124,7 @@ public class UriTemplateUnitTest {
 
 		UriTemplate template = new UriTemplate("/foo{?bar}");
 
-		URI uri = template.expand(Collections.<String, Object> singletonMap("bar", "myBar"));
+		URI uri = template.expand(Collections.singletonMap("bar", "myBar"));
 		assertThat(uri.toString(), is("/foo?bar=myBar"));
 	}