diff --git a/classes/admin/admin_setting_configcheckbox.php b/classes/admin/admin_setting_configcheckbox.php
index 35352bd3..0fb374f9 100644
--- a/classes/admin/admin_setting_configcheckbox.php
+++ b/classes/admin/admin_setting_configcheckbox.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\admin;
 
-use tool_dataflows\admin\readonly_trait;
 
 /**
  * A custom class applying extra readonly checks to the base implementation.
diff --git a/classes/admin/admin_setting_configexecutable.php b/classes/admin/admin_setting_configexecutable.php
index 8d48ffdb..2f9c413c 100644
--- a/classes/admin/admin_setting_configexecutable.php
+++ b/classes/admin/admin_setting_configexecutable.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\admin;
 
-use tool_dataflows\admin\readonly_trait;
 
 /**
  * A custom class applying extra readonly checks to the base implementation.
diff --git a/classes/admin/admin_setting_configmultiselect.php b/classes/admin/admin_setting_configmultiselect.php
index 9f74ce38..749d698d 100644
--- a/classes/admin/admin_setting_configmultiselect.php
+++ b/classes/admin/admin_setting_configmultiselect.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\admin;
 
-use tool_dataflows\admin\readonly_trait;
 
 /**
  * A custom class applying extra readonly checks to the base implementation.
diff --git a/classes/admin/admin_setting_configtext.php b/classes/admin/admin_setting_configtext.php
index 159e9d6c..708efdf7 100644
--- a/classes/admin/admin_setting_configtext.php
+++ b/classes/admin/admin_setting_configtext.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\admin;
 
-use tool_dataflows\admin\readonly_trait;
 
 /**
  * A custom class applying extra readonly checks to the base implementation.
diff --git a/classes/local/execution/flow_engine_step.php b/classes/local/execution/flow_engine_step.php
index d40128f9..47ebddc0 100644
--- a/classes/local/execution/flow_engine_step.php
+++ b/classes/local/execution/flow_engine_step.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\local\execution;
 
-use tool_dataflows\parser;
 
 /**
  * Manages the execution of a flow step.
diff --git a/classes/local/execution/iterators/dataflow_iterator.php b/classes/local/execution/iterators/dataflow_iterator.php
index 372ce15c..a6d8386b 100644
--- a/classes/local/execution/iterators/dataflow_iterator.php
+++ b/classes/local/execution/iterators/dataflow_iterator.php
@@ -18,7 +18,6 @@
 
 use tool_dataflows\local\execution\flow_engine_step;
 use tool_dataflows\local\step\base_step;
-use tool_dataflows\local\step\flow_cap;
 
 /**
  * A mapping iterator that takes a PHP iterator as a source.
diff --git a/classes/local/execution/logging/mtrace_handler.php b/classes/local/execution/logging/mtrace_handler.php
index 32e31330..5d8cef10 100644
--- a/classes/local/execution/logging/mtrace_handler.php
+++ b/classes/local/execution/logging/mtrace_handler.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\local\execution\logging;
 
-use Monolog\Handler\AbstractHandler;
 use Monolog\Handler\AbstractProcessingHandler;
 
 /**
diff --git a/classes/local/provider/expression_provider.php b/classes/local/provider/expression_provider.php
index bcd64048..8461591a 100644
--- a/classes/local/provider/expression_provider.php
+++ b/classes/local/provider/expression_provider.php
@@ -18,7 +18,6 @@
 
 use Symfony\Component\ExpressionLanguage\ExpressionFunction;
 use Symfony\Component\ExpressionLanguage\ExpressionFunctionProviderInterface;
-use tool_dataflows\parser;
 
 /**
  * Expression Provider
diff --git a/classes/local/service/step_service.php b/classes/local/service/step_service.php
index 757ed90e..211d7d7b 100644
--- a/classes/local/service/step_service.php
+++ b/classes/local/service/step_service.php
@@ -18,7 +18,6 @@
 
 use tool_dataflows\local\execution\engine_flow_cap;
 use tool_dataflows\local\execution\engine_step;
-use tool_dataflows\local\step\reader_step;
 use tool_dataflows\step;
 
 /**
diff --git a/classes/local/step/base_step.php b/classes/local/step/base_step.php
index be8f1ebb..3eb14501 100644
--- a/classes/local/step/base_step.php
+++ b/classes/local/step/base_step.php
@@ -22,7 +22,6 @@
 use tool_dataflows\local\execution\engine_step;
 use tool_dataflows\local\variables\var_root;
 use tool_dataflows\local\variables\var_step;
-use tool_dataflows\parser;
 use tool_dataflows\step;
 
 /**
diff --git a/classes/local/step/connector_copy_file.php b/classes/local/step/connector_copy_file.php
index 60ebdcd3..90ecadf9 100644
--- a/classes/local/step/connector_copy_file.php
+++ b/classes/local/step/connector_copy_file.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\local\step;
 
-use tool_dataflows\helper;
 
 /**
  * Copy file connector step
diff --git a/classes/local/step/connector_debug_file_display.php b/classes/local/step/connector_debug_file_display.php
index b2b06e5a..87de1b28 100644
--- a/classes/local/step/connector_debug_file_display.php
+++ b/classes/local/step/connector_debug_file_display.php
@@ -15,7 +15,6 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 namespace tool_dataflows\local\step;
-use tool_dataflows\local\execution\engine_step;
 use tool_dataflows\helper;
 
 /**
diff --git a/classes/local/step/connector_debugging.php b/classes/local/step/connector_debugging.php
index 124b880b..1f50afab 100644
--- a/classes/local/step/connector_debugging.php
+++ b/classes/local/step/connector_debugging.php
@@ -15,7 +15,6 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 namespace tool_dataflows\local\step;
-use tool_dataflows\local\execution\engine_step;
 
 /**
  * Debugging connector step type
diff --git a/classes/local/step/connector_sftp.php b/classes/local/step/connector_sftp.php
index aeff021c..def22769 100644
--- a/classes/local/step/connector_sftp.php
+++ b/classes/local/step/connector_sftp.php
@@ -16,10 +16,7 @@
 
 namespace tool_dataflows\local\step;
 
-use phpseclib3\Crypt\Common\AsymmetricKey;
-use phpseclib3\Crypt\PublicKeyLoader;
 use phpseclib3\Net\SFTP;
-use tool_dataflows\helper;
 
 /**
  * SFTP connector step type.
diff --git a/classes/local/step/curl_trait.php b/classes/local/step/curl_trait.php
index 6c702917..7af69ec6 100644
--- a/classes/local/step/curl_trait.php
+++ b/classes/local/step/curl_trait.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\local\step;
 
-use Symfony\Component\Yaml\Yaml;
 use tool_dataflows\helper;
 
 defined('MOODLE_INTERNAL') || die();
diff --git a/classes/local/step/flow_copy_file.php b/classes/local/step/flow_copy_file.php
index f2a97c4a..ed9b8d9b 100644
--- a/classes/local/step/flow_copy_file.php
+++ b/classes/local/step/flow_copy_file.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\local\step;
 
-use tool_dataflows\helper;
 
 /**
  * Copy file flow step
diff --git a/classes/local/step/flow_sftp.php b/classes/local/step/flow_sftp.php
index 9cccd09b..dc5cb67c 100644
--- a/classes/local/step/flow_sftp.php
+++ b/classes/local/step/flow_sftp.php
@@ -16,10 +16,7 @@
 
 namespace tool_dataflows\local\step;
 
-use phpseclib3\Crypt\Common\AsymmetricKey;
-use phpseclib3\Crypt\PublicKeyLoader;
 use phpseclib3\Net\SFTP;
-use tool_dataflows\helper;
 
 /**
  * SFTP connector step type.
diff --git a/classes/local/step/flow_web_service.php b/classes/local/step/flow_web_service.php
index a3d623dd..6f5c27e9 100644
--- a/classes/local/step/flow_web_service.php
+++ b/classes/local/step/flow_web_service.php
@@ -24,7 +24,6 @@
 use core\session\manager;
 use external_api;
 use moodle_exception;
-use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
 use Symfony\Component\Yaml\Yaml;
 use Throwable;
 use tool_dataflows\parser;
diff --git a/classes/local/step/set_multiple_variables_trait.php b/classes/local/step/set_multiple_variables_trait.php
index 6d2ea232..75655d46 100644
--- a/classes/local/step/set_multiple_variables_trait.php
+++ b/classes/local/step/set_multiple_variables_trait.php
@@ -17,7 +17,6 @@
 namespace tool_dataflows\local\step;
 
 use tool_dataflows\local\variables\var_root;
-use tool_dataflows\local\variables\var_object_visible;
 
 /**
  * Set multiple variables trait
diff --git a/classes/local/step/sftp_trait.php b/classes/local/step/sftp_trait.php
index eff76213..f44a7ee7 100644
--- a/classes/local/step/sftp_trait.php
+++ b/classes/local/step/sftp_trait.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\local\step;
 
-use MoodleQuickForm;
 use phpseclib3\Crypt\Common\AsymmetricKey;
 use phpseclib3\Crypt\PublicKeyLoader;
 use phpseclib3\Net\SFTP;
diff --git a/classes/local/step/trigger_step.php b/classes/local/step/trigger_step.php
index 4c5e26ea..ff363cdc 100644
--- a/classes/local/step/trigger_step.php
+++ b/classes/local/step/trigger_step.php
@@ -16,11 +16,6 @@
 
 namespace tool_dataflows\local\step;
 
-use tool_dataflows\local\execution\engine;
-use tool_dataflows\local\execution\iterators\iterator;
-use tool_dataflows\local\execution\iterators\dataflow_iterator;
-use tool_dataflows\local\execution\flow_engine_step;
-use tool_dataflows\local\execution\engine_step;
 
 /**
  * Base class for trigger step types.
diff --git a/classes/local/variables/var_dataflow.php b/classes/local/variables/var_dataflow.php
index 4eed658c..373f1659 100644
--- a/classes/local/variables/var_dataflow.php
+++ b/classes/local/variables/var_dataflow.php
@@ -16,9 +16,7 @@
 
 namespace tool_dataflows\local\variables;
 
-use Symfony\Component\Yaml\Yaml;
 use tool_dataflows\dataflow;
-use tool_dataflows\helper;
 use tool_dataflows\local\execution\engine;
 
 /**
diff --git a/classes/parser.php b/classes/parser.php
index 9bc309aa..bf436f7b 100644
--- a/classes/parser.php
+++ b/classes/parser.php
@@ -20,7 +20,6 @@
 use Symfony\Component\Cache\Adapter\FilesystemAdapter;
 use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
 use Symfony\Component\ExpressionLanguage\Lexer;
-use Symfony\Component\ExpressionLanguage\Node;
 use Symfony\Component\ExpressionLanguage\Token;
 use Symfony\Component\ExpressionLanguage\TokenStream;
 use Symfony\Component\Yaml\Exception\ParseException;
diff --git a/classes/task/process_dataflows.php b/classes/task/process_dataflows.php
index 872067d9..fcfc381b 100644
--- a/classes/task/process_dataflows.php
+++ b/classes/task/process_dataflows.php
@@ -20,7 +20,6 @@
 use tool_dataflows\local\execution\engine;
 use tool_dataflows\local\scheduler;
 use tool_dataflows\local\event_processor;
-use tool_dataflows\task\process_dataflow_ad_hoc;
 
 /**
  * Process queued dataflows.
diff --git a/tests/local/execution/array_in_type.php b/tests/local/execution/array_in_type.php
index 07fc2a23..77490dbf 100644
--- a/tests/local/execution/array_in_type.php
+++ b/tests/local/execution/array_in_type.php
@@ -18,7 +18,6 @@
 
 use tool_dataflows\local\execution\iterators\iterator;
 use tool_dataflows\local\execution\iterators\dataflow_iterator;
-use tool_dataflows\local\execution\flow_engine_step;
 use tool_dataflows\local\step\reader_step;
 
 /**
diff --git a/tests/local/execution/array_out_type.php b/tests/local/execution/array_out_type.php
index df98a584..604ed86e 100644
--- a/tests/local/execution/array_out_type.php
+++ b/tests/local/execution/array_out_type.php
@@ -18,7 +18,6 @@
 
 use tool_dataflows\local\execution\iterators\iterator;
 use tool_dataflows\local\execution\iterators\dataflow_iterator;
-use tool_dataflows\local\execution\flow_engine_step;
 use tool_dataflows\local\step\writer_step;
 
 /**
diff --git a/tests/local/execution/direct_in_type.php b/tests/local/execution/direct_in_type.php
index 9498f13e..225c66b2 100644
--- a/tests/local/execution/direct_in_type.php
+++ b/tests/local/execution/direct_in_type.php
@@ -16,10 +16,8 @@
 
 namespace tool_dataflows\local\execution;
 
-use Symfony\Component\Yaml\Yaml;
 use tool_dataflows\local\execution\iterators\iterator;
 use tool_dataflows\local\execution\iterators\dataflow_iterator;
-use tool_dataflows\local\execution\flow_engine_step;
 use tool_dataflows\local\step\reader_step;
 
 /**
diff --git a/tests/local/execution/flow_callback_step.php b/tests/local/execution/flow_callback_step.php
index d78a4861..c62b860f 100644
--- a/tests/local/execution/flow_callback_step.php
+++ b/tests/local/execution/flow_callback_step.php
@@ -16,9 +16,6 @@
 
 namespace tool_dataflows\local\execution;
 
-use tool_dataflows\local\execution\iterators\iterator;
-use tool_dataflows\local\execution\iterators\dataflow_iterator;
-use tool_dataflows\local\execution\flow_engine_step;
 use tool_dataflows\local\step\flow_step;
 
 /**
diff --git a/tests/local/execution/test_engine.php b/tests/local/execution/test_engine.php
index e37e5b89..717feb2a 100644
--- a/tests/local/execution/test_engine.php
+++ b/tests/local/execution/test_engine.php
@@ -16,8 +16,6 @@
 
 namespace tool_dataflows\local\execution;
 
-use tool_dataflows\dataflow;
-use tool_dataflows\step;
 
 /**
  * A engine subclass used for testing
diff --git a/tests/local/execution/tool_dataflows_basic_execution_test.php b/tests/local/execution/tool_dataflows_basic_execution_test.php
index 9ef3981f..404b80aa 100644
--- a/tests/local/execution/tool_dataflows_basic_execution_test.php
+++ b/tests/local/execution/tool_dataflows_basic_execution_test.php
@@ -17,7 +17,6 @@
 namespace tool_dataflows\local\execution;
 
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\local\execution\engine;
 use tool_dataflows\dataflow;
 use tool_dataflows\step;
 use tool_dataflows\test_dataflows;
diff --git a/tests/tool_dataflows_concurrency_test.php b/tests/tool_dataflows_concurrency_test.php
index 245fef22..d248edbe 100644
--- a/tests/tool_dataflows_concurrency_test.php
+++ b/tests/tool_dataflows_concurrency_test.php
@@ -17,8 +17,6 @@
 namespace tool_dataflows;
 
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\step;
-use tool_dataflows\dataflow;
 
 /**
  * tests some of the code around concurrency.
diff --git a/tests/tool_dataflows_connector_curl_test.php b/tests/tool_dataflows_connector_curl_test.php
index ffeb60c2..8d3df5ed 100644
--- a/tests/tool_dataflows_connector_curl_test.php
+++ b/tests/tool_dataflows_connector_curl_test.php
@@ -20,8 +20,6 @@
 use Symfony\Component\Yaml\Yaml;
 use tool_dataflows\local\step\connector_curl;
 use tool_dataflows\local\execution\engine;
-use tool_dataflows\step;
-use tool_dataflows\dataflow;
 
 defined('MOODLE_INTERNAL') || die();
 
diff --git a/tests/tool_dataflows_connector_debug_file_display_test.php b/tests/tool_dataflows_connector_debug_file_display_test.php
index cdcbe73c..cf6c3657 100644
--- a/tests/tool_dataflows_connector_debug_file_display_test.php
+++ b/tests/tool_dataflows_connector_debug_file_display_test.php
@@ -20,7 +20,6 @@
 use tool_dataflows\local\execution\engine;
 use tool_dataflows\local\execution\direct_in_type;
 use tool_dataflows\local\step\connector_debug_file_display;
-use tool_dataflows\local\step\writer_stream;
 
 defined('MOODLE_INTERNAL') || die();
 
diff --git a/tests/tool_dataflows_dot_escape_test.php b/tests/tool_dataflows_dot_escape_test.php
index d01c9c05..36164f18 100644
--- a/tests/tool_dataflows_dot_escape_test.php
+++ b/tests/tool_dataflows_dot_escape_test.php
@@ -17,8 +17,6 @@
 namespace tool_dataflows;
 
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\local\execution\engine;
-use tool_dataflows\local\step\reader_json;
 
 defined('MOODLE_INTERNAL') || die();
 
diff --git a/tests/tool_dataflows_flow_set_variable_test.php b/tests/tool_dataflows_flow_set_variable_test.php
index dc925aa1..6756c3d8 100644
--- a/tests/tool_dataflows_flow_set_variable_test.php
+++ b/tests/tool_dataflows_flow_set_variable_test.php
@@ -22,7 +22,6 @@
 use tool_dataflows\local\execution\engine;
 use tool_dataflows\local\step\flow_abort;
 use tool_dataflows\local\step\flow_set_variable;
-use tool_dataflows\test_dataflows;
 
 defined('MOODLE_INTERNAL') || die();
 
diff --git a/tests/tool_dataflows_flow_sql_test.php b/tests/tool_dataflows_flow_sql_test.php
index 001cb301..9a21bee1 100644
--- a/tests/tool_dataflows_flow_sql_test.php
+++ b/tests/tool_dataflows_flow_sql_test.php
@@ -17,9 +17,7 @@
 namespace tool_dataflows;
 
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\dataflow;
 use tool_dataflows\local\execution\engine;
-use tool_dataflows\step;
 use tool_dataflows\local\step\flow_sql;
 
 defined('MOODLE_INTERNAL') || die();
diff --git a/tests/tool_dataflows_gpg_test.php b/tests/tool_dataflows_gpg_test.php
index 176bf5b4..c4e0f305 100644
--- a/tests/tool_dataflows_gpg_test.php
+++ b/tests/tool_dataflows_gpg_test.php
@@ -17,7 +17,6 @@
 namespace tool_dataflows;
 
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\local\execution\engine;
 use tool_dataflows\local\step\connector_gpg;
 
 /**
diff --git a/tests/tool_dataflows_secret_service_test.php b/tests/tool_dataflows_secret_service_test.php
index b9c7c7ac..e426ef0a 100644
--- a/tests/tool_dataflows_secret_service_test.php
+++ b/tests/tool_dataflows_secret_service_test.php
@@ -26,11 +26,9 @@
 namespace tool_dataflows;
 
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\application_trait;
 use tool_dataflows\local\execution\engine;
 use tool_dataflows\local\service\secret_service;
 use tool_dataflows\local\step\connector_s3;
-use tool_dataflows\step;
 
 defined('MOODLE_INTERNAL') || die();
 
diff --git a/tests/tool_dataflows_sql_reader_test.php b/tests/tool_dataflows_sql_reader_test.php
index 9aad1810..007a065f 100644
--- a/tests/tool_dataflows_sql_reader_test.php
+++ b/tests/tool_dataflows_sql_reader_test.php
@@ -17,9 +17,7 @@
 namespace tool_dataflows;
 
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\dataflow;
 use tool_dataflows\local\execution\engine;
-use tool_dataflows\step;
 use tool_dataflows\local\step\reader_sql;
 
 defined('MOODLE_INTERNAL') || die();
diff --git a/tests/tool_dataflows_stream_writer_test.php b/tests/tool_dataflows_stream_writer_test.php
index cc975525..c0534fed 100644
--- a/tests/tool_dataflows_stream_writer_test.php
+++ b/tests/tool_dataflows_stream_writer_test.php
@@ -17,10 +17,8 @@
 namespace tool_dataflows;
 
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\dataflow;
 use tool_dataflows\local\execution\engine;
 use tool_dataflows\local\step\writer_stream;
-use tool_dataflows\step;
 
 defined('MOODLE_INTERNAL') || die();
 
diff --git a/tests/tool_dataflows_test.php b/tests/tool_dataflows_test.php
index 50ce0010..09760fb8 100644
--- a/tests/tool_dataflows_test.php
+++ b/tests/tool_dataflows_test.php
@@ -18,7 +18,6 @@
 
 use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\application_trait;
 use tool_dataflows\local\scheduler;
 use tool_dataflows\local\step;
 
diff --git a/tests/tool_dataflows_variables_new_test.php b/tests/tool_dataflows_variables_new_test.php
index c374150f..0da91cd2 100644
--- a/tests/tool_dataflows_variables_new_test.php
+++ b/tests/tool_dataflows_variables_new_test.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows;
 
-use tool_dataflows\local\variables\var_value;
 
 defined('MOODLE_INTERNAL') || die();
 
diff --git a/tests/tool_dataflows_variables_test.php b/tests/tool_dataflows_variables_test.php
index c376a453..b630adbb 100644
--- a/tests/tool_dataflows_variables_test.php
+++ b/tests/tool_dataflows_variables_test.php
@@ -18,9 +18,7 @@
 
 use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\dataflow;
 use tool_dataflows\local\execution\engine;
-use tool_dataflows\step;
 use tool_dataflows\local\execution;
 use tool_dataflows\local\step\connector_curl;
 use tool_dataflows\local\step\connector_debugging;
diff --git a/tests/tool_dataflows_web_service_flow_test.php b/tests/tool_dataflows_web_service_flow_test.php
index 969446e8..c06328f5 100644
--- a/tests/tool_dataflows_web_service_flow_test.php
+++ b/tests/tool_dataflows_web_service_flow_test.php
@@ -20,12 +20,9 @@
 
 require_once(__DIR__ . '/application_trait.php');
 
-use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
 use Symfony\Component\Yaml\Yaml;
-use tool_dataflows\dataflow;
 use tool_dataflows\local\execution\engine;
 use tool_dataflows\local\step\flow_web_service;
-use tool_dataflows\step;
 
 /**
  * Unit test for the web service flow step.