diff --git a/src/wp-includes/ms-blogs.php b/src/wp-includes/ms-blogs.php
index 72ebbaa3a8..d291f169db 100644
--- a/src/wp-includes/ms-blogs.php
+++ b/src/wp-includes/ms-blogs.php
@@ -33,11 +33,11 @@ function wpmu_update_blogs_date() {
  * @since MU
  *
  * @param int $blog_id Blog ID
- * @return string
+ * @return string Full URL of the blog if found. Empty string if not.
  */
 function get_blogaddress_by_id( $blog_id ) {
 	$bloginfo = get_blog_details( (int) $blog_id, false ); // only get bare details!
-	return esc_url( 'http://' . $bloginfo->domain . $bloginfo->path );
+	return isset( $bloginfo->domain ) && isset( $bloginfo->path ) ?  esc_url( 'http://' . $bloginfo->domain . $bloginfo->path ) : '';
 }
 
 /**
diff --git a/tests/phpunit/tests/multisite/site.php b/tests/phpunit/tests/multisite/site.php
index 73cbd2872b..603546c3c7 100644
--- a/tests/phpunit/tests/multisite/site.php
+++ b/tests/phpunit/tests/multisite/site.php
@@ -332,7 +332,7 @@ class Tests_Multisite_Site extends WP_UnitTestCase {
 		$result = update_blog_details( 999, array( 'domain' => 'example.com' ) );
 		$this->assertFalse( $result );
 	}
-	
+
 	function test_update_blog_details() {
 		$blog_id = $this->factory->blog->create();
 
@@ -1461,6 +1461,22 @@ class Tests_Multisite_Site extends WP_UnitTestCase {
 
 		remove_filter( 'domain_exists', array( $this, '_domain_exists_cb' ), 10, 4 );
 	}
+
+	/**
+	 * Tests returning an address for a given valid id.
+	 */
+	function test_get_blogaddress_by_id_with_valid_id() {
+		$blogaddress = get_blogaddress_by_id( 1 );
+		$this->assertEquals( 'http://example.org/', $blogaddress );
+	}
+
+	/**
+	 * Tests returning the appropriate response for a invalid id given.
+	 */
+	function test_get_blogaddress_by_id_with_invalid_id() {
+		$blogaddress = get_blogaddress_by_id( 42 );
+		$this->assertEquals( '', $blogaddress );
+	}
 }
 
 endif;
\ No newline at end of file