diff --git a/spring-web/src/main/java/org/springframework/http/client/support/BasicAuthorizationInterceptor.java b/spring-web/src/main/java/org/springframework/http/client/support/BasicAuthorizationInterceptor.java
index 5ebb76a3a61..b29a412732c 100644
--- a/spring-web/src/main/java/org/springframework/http/client/support/BasicAuthorizationInterceptor.java
+++ b/spring-web/src/main/java/org/springframework/http/client/support/BasicAuthorizationInterceptor.java
@@ -46,9 +46,9 @@ public class BasicAuthorizationInterceptor implements ClientHttpRequestIntercept
 	 * @param username the username to use
 	 * @param password the password to use
 	 */
-	public BasicAuthorizationInterceptor(String username, @Nullable String password) {
-		Assert.hasLength(username, "Username must not be empty");
-		this.username = username;
+	public BasicAuthorizationInterceptor(@Nullable String username, @Nullable String password) {
+		Assert.doesNotContain(username, ":", "Username must not contain a colon");
+		this.username = (username != null ? username : "");
 		this.password = (password != null ? password : "");
 	}
 
diff --git a/spring-web/src/test/java/org/springframework/http/client/support/BasicAuthorizationInterceptorTests.java b/spring-web/src/test/java/org/springframework/http/client/support/BasicAuthorizationInterceptorTests.java
index ce96460dc0c..844fd8aa929 100644
--- a/spring-web/src/test/java/org/springframework/http/client/support/BasicAuthorizationInterceptorTests.java
+++ b/spring-web/src/test/java/org/springframework/http/client/support/BasicAuthorizationInterceptorTests.java
@@ -43,17 +43,17 @@ public class BasicAuthorizationInterceptorTests {
 	public ExpectedException thrown = ExpectedException.none();
 
 	@Test
-	public void createWhenUsernameIsNullShouldThrowException() {
+	public void createWhenUsernameContainsColonShouldThrowException() {
 		this.thrown.expect(IllegalArgumentException.class);
-		this.thrown.expectMessage("Username must not be empty");
-		new BasicAuthorizationInterceptor(null, "password");
+		this.thrown.expectMessage("Username must not contain a colon");
+		new BasicAuthorizationInterceptor("username:", "password");
 	}
 
 	@Test
-	public void createWhenUsernameIsEmptyShouldThrowException() throws Exception {
-		this.thrown.expect(IllegalArgumentException.class);
-		this.thrown.expectMessage("Username must not be empty");
-		new BasicAuthorizationInterceptor("", "password");
+	public void createWhenUsernameIsNullShouldUseEmptyUsername() throws Exception {
+		BasicAuthorizationInterceptor interceptor = new BasicAuthorizationInterceptor(
+				null, "password");
+		assertEquals("", new DirectFieldAccessor(interceptor).getPropertyValue("username"));
 	}
 
 	@Test