diff --git a/mod/data/classes/external.php b/mod/data/classes/external.php
index e71c98c162c..65670ef0728 100644
--- a/mod/data/classes/external.php
+++ b/mod/data/classes/external.php
@@ -596,7 +596,7 @@ class mod_data_external extends external_api {
 
         $params = array('databaseid' => $databaseid);
         $params = self::validate_parameters(self::get_fields_parameters(), $params);
-        $warnings = array();
+        $fields = $warnings = array();
 
         list($database, $course, $cm, $context) = self::validate_database($params['databaseid']);
 
diff --git a/mod/data/tests/externallib_test.php b/mod/data/tests/externallib_test.php
index 1b61d09bf49..e9310b000b0 100644
--- a/mod/data/tests/externallib_test.php
+++ b/mod/data/tests/externallib_test.php
@@ -659,6 +659,18 @@ class mod_data_external_testcase extends externallib_advanced_testcase {
         }
     }
 
+    /**
+     * Test get_fields_database_without_fields.
+     */
+    public function test_get_fields_database_without_fields() {
+
+        $this->setUser($this->student1);
+        $result = mod_data_external::get_fields($this->database->id);
+        $result = external_api::clean_returnvalue(mod_data_external::get_fields_returns(), $result);
+
+        $this->assertEmpty($result['fields']);
+    }
+
     /**
      * Test search_entries.
      */