diff --git a/Database/Query.php b/Database/Query.php
index 63bf004..8444799 100644
--- a/Database/Query.php
+++ b/Database/Query.php
@@ -610,15 +610,15 @@ public function set($set, $val = null, $bind = true)
 	 * Can be used in two different ways, as where( field, value ) or as an array of
 	 * conditions to use: where( array('fieldName', ...), array('value', ...) );
 	 *
-	 * @param string|string[]|callable $key   Single field name, or an array of field names.
-	 *                                        If given as a function (i.e. a closure), the function is called, passing the
-	 *                                        query itself in as the only parameter, so the function can add extra conditions
-	 *                                        with parentheses around the additional parameters.
-	 * @param string|string[]          $value Single field value, or an array of
-	 *                                        values. Can be null to search for `IS NULL` or `IS NOT NULL` (depending
-	 *                                        on the value of `$op` which should be `=` or `!=`.
-	 * @param string                   $op    Condition operator: <, >, = etc
-	 * @param bool                     $bind  Escape the value (true, default) or not (false).
+	 * @param string|string[]|\Closure($this): void $key   Single field name, or an array of field names.
+	 *                                                     If given as a function (i.e. a closure), the function is called, passing the
+	 *                                                     query itself in as the only parameter, so the function can add extra conditions
+	 *                                                     with parentheses around the additional parameters.
+	 * @param string|string[]                       $value Single field value, or an array of
+	 *                                                     values. Can be null to search for `IS NULL` or `IS NOT NULL` (depending
+	 *                                                     on the value of `$op` which should be `=` or `!=`.
+	 * @param string                                $op    Condition operator: <, >, = etc
+	 * @param bool                                  $bind  Escape the value (true, default) or not (false).
 	 *
 	 * @return $this
 	 *
@@ -661,15 +661,15 @@ public function where($key, $value = null, $op = '=', $bind = true)
 	 * Can be used in two different ways, as where( field, value ) or as an array of
 	 * conditions to use: where( array('fieldName', ...), array('value', ...) );
 	 *
-	 * @param string|string[]|callable $key   Single field name, or an array of field names.
-	 *                                        If given as a function (i.e. a closure), the function is called, passing the
-	 *                                        query itself in as the only parameter, so the function can add extra conditions
-	 *                                        with parentheses around the additional parameters.
-	 * @param string|string[]          $value Single field value, or an array of
-	 *                                        values. Can be null to search for `IS NULL` or `IS NOT NULL` (depending
-	 *                                        on the value of `$op` which should be `=` or `!=`.
-	 * @param string                   $op    Condition operator: <, >, = etc
-	 * @param bool                     $bind  Escape the value (true, default) or not (false).
+	 * @param string|string[]|\Closure($this): void $key   Single field name, or an array of field names.
+	 *                                                     If given as a function (i.e. a closure), the function is called, passing the
+	 *                                                     query itself in as the only parameter, so the function can add extra conditions
+	 *                                                     with parentheses around the additional parameters.
+	 * @param string|string[]                       $value Single field value, or an array of
+	 *                                                     values. Can be null to search for `IS NULL` or `IS NOT NULL` (depending
+	 *                                                     on the value of `$op` which should be `=` or `!=`.
+	 * @param string                                $op    Condition operator: <, >, = etc
+	 * @param bool                                  $bind  Escape the value (true, default) or not (false).
 	 *
 	 * @return $this
 	 */
@@ -684,15 +684,15 @@ public function and_where($key, $value = null, $op = '=', $bind = true)
 	 * Can be used in two different ways, as where( field, value ) or as an array of
 	 * conditions to use: where( array('fieldName', ...), array('value', ...) );
 	 *
-	 * @param string|string[]|callable $key   Single field name, or an array of field names.
-	 *                                        If given as a function (i.e. a closure), the function is called, passing the
-	 *                                        query itself in as the only parameter, so the function can add extra conditions
-	 *                                        with parentheses around the additional parameters.
-	 * @param string|string[]          $value Single field value, or an array of
-	 *                                        values. Can be null to search for `IS NULL` or `IS NOT NULL` (depending
-	 *                                        on the value of `$op` which should be `=` or `!=`.
-	 * @param string                   $op    Condition operator: <, >, = etc
-	 * @param bool                     $bind  Escape the value (true, default) or not (false).
+	 * @param string|string[]|\Closure($this): void $key   Single field name, or an array of field names.
+	 *                                                     If given as a function (i.e. a closure), the function is called, passing the
+	 *                                                     query itself in as the only parameter, so the function can add extra conditions
+	 *                                                     with parentheses around the additional parameters.
+	 * @param string|string[]                       $value Single field value, or an array of
+	 *                                                     values. Can be null to search for `IS NULL` or `IS NOT NULL` (depending
+	 *                                                     on the value of `$op` which should be `=` or `!=`.
+	 * @param string                                $op    Condition operator: <, >, = etc
+	 * @param bool                                  $bind  Escape the value (true, default) or not (false).
 	 *
 	 * @return $this
 	 */
@@ -727,11 +727,11 @@ public function or_where($key, $value = null, $op = '=', $bind = true)
 	 * define if a grouping bracket should be opened or closed in the query.
 	 * This method is not prefer.
 	 *
-	 * @param bool|callable $inOut If callable it will create the group
-	 *                             automatically and pass the query into the called function. For
-	 *                             legacy operations use `true` to open brackets, `false` to close.
-	 * @param string        $op    Conditional operator to use to join to the
-	 *                             preceding condition. Default `AND`.
+	 * @param bool|\Closure($this): void $inOut If callable it will create the group
+	 *                                          automatically and pass the query into the called function. For
+	 *                                          legacy operations use `true` to open brackets, `false` to close.
+	 * @param string                     $op    Conditional operator to use to join to the
+	 *                                          preceding condition. Default `AND`.
 	 *
 	 * @return $this
 	 *
diff --git a/Editor.php b/Editor.php
index b8c8b52..2795f8f 100644
--- a/Editor.php
+++ b/Editor.php
@@ -17,6 +17,7 @@
 namespace DataTables;
 
 use DataTables;
+use DataTables\Database\Query;
 use DataTables\Editor\Field;
 use DataTables\Editor\Join;
 
@@ -561,9 +562,9 @@ public function leftJoinRemove($_ = null)
 	 * Add an event listener. The `Editor` class will trigger an number of
 	 * events that some action can be taken on.
 	 *
-	 * @param string   $name     Event name
-	 * @param callable $callback Callback function to execute when the event
-	 *                           occurs
+	 * @param string                                                     $name     Event name
+	 * @param callable($this, mixed, mixed, mixed, mixed, mixed): ?false $callback Callback function to execute when the event
+	 *                                                                             occurs
 	 *
 	 * @return $this
 	 */
@@ -859,9 +860,9 @@ public function validate(&$errors, $data)
 	 * and remove actions performed from the client-side. Multiple validators
 	 * can be added.
 	 *
-	 * @param callable $_ Function to execute when validating the input data.
-	 *                    It is passed three parameters: 1. The editor instance, 2. The action
-	 *                    and 3. The values.
+	 * @param callable($this, self::ACTION_*, array): ?string $_ Function to execute when validating the input data.
+	 *                                                           It is passed three parameters: 1. The editor instance, 2. The action
+	 *                                                           and 3. The values.
 	 *
 	 * @return ($_ is null ? callable : $this) The validator function.
 	 */
@@ -890,9 +891,9 @@ public function validator($_ = null)
 	 * undefined (since Editor expects the row to still be available, but the
 	 * condition removes it from the result set).
 	 *
-	 * @param string|callable $key   Single field name or a closure function
-	 * @param string          $value Single field value.
-	 * @param string          $op    Condition operator: <, >, = etc
+	 * @param string|\Closure(Query): void $key   Single field name or a closure function
+	 * @param string                       $value Single field value.
+	 * @param string                       $op    Condition operator: <, >, = etc
 	 *
 	 * @return ($key is null ? string[] : $this) Where condition array.
 	 */
@@ -2047,7 +2048,7 @@ private function _ssp_limit($query, $http)
 	private function _get_where($query)
 	{
 		for ($i = 0; $i < count($this->_where); ++$i) {
-			if (is_callable($this->_where[$i])) {
+			if ($this->_where[$i] instanceof \Closure) {
 				$this->_where[$i]($query);
 			} else {
 				$query->where(
@@ -2220,7 +2221,7 @@ private function _insert_or_update_table($table, $values, $where = null)
 			for ($j = 0, $jen = count($this->_where); $j < $jen; ++$j) {
 				$cond = $this->_where[$j];
 
-				if (!is_callable($cond)) {
+				if (!$cond instanceof \Closure) {
 					// Make sure the value wasn't in the submitted data set,
 					// otherwise we would be overwriting it
 					if (!isset($set[$cond['key']])) {
diff --git a/Editor/Field.php b/Editor/Field.php
index 3a0f208..050c0f7 100644
--- a/Editor/Field.php
+++ b/Editor/Field.php
@@ -14,6 +14,8 @@
 namespace DataTables\Editor;
 
 use DataTables;
+use DataTables\Database;
+use DataTables\Database\Query;
 use DataTables\Editor;
 use DataTables\HtmLawed\Htmlaw;
 
@@ -228,13 +230,13 @@ public function get($_ = null)
 	 * Editor has a number of formatters available with the {@see Format} class
 	 * which can be used directly with this method.
 	 *
-	 * @param callable|string $_    Value to set if using as a setter. Can be given as
-	 *                              a closure function or a string with a reference to a function that will
-	 *                              be called with call_user_func().
-	 * @param mixed           $opts Variable that is passed through to the get formatting
-	 *                              function - can be useful for passing through extra information such as
-	 *                              date formatting string, or a required flag. The actual options available
-	 *                              depend upon the formatter used.
+	 * @param callable(mixed, array, array): string $_    Value to set if using as a setter. Can be given as
+	 *                                                    a closure function or a string with a reference to a function that will
+	 *                                                    be called with call_user_func().
+	 * @param mixed                                 $opts Variable that is passed through to the get formatting
+	 *                                                    function - can be useful for passing through extra information such as
+	 *                                                    date formatting string, or a required flag. The actual options available
+	 *                                                    depend upon the formatter used.
 	 *
 	 * @return ($_ is null ? callable|string : $this) The get formatter if no parameter is given.
 	 */
@@ -251,8 +253,8 @@ public function getFormatter($_ = null, $opts = null)
 	 * Get / set a get value. If given, then this value is used to send to the
 	 * client-side, regardless of what value is held by the database.
 	 *
-	 * @param callable|string|number $_ Value to set, or no value to use as a
-	 *                                  getter
+	 * @param \Closure(): mixed|string|number $_ Value to set, or no value to use as a
+	 *                                           getter
 	 *
 	 * @return ($_ is null ? callable|string : $this) Value if used as a getter.
 	 */
@@ -286,16 +288,16 @@ public function name($_ = null)
 	 * data, including pairs that require joins and where conditions, use a
 	 * closure to provide a query
 	 *
-	 * @param string|callable $table     Database table name to use to get the
-	 *                                   paired data from, or a closure function if providing a method
-	 * @param string          $value     Table column name that contains the pair's
-	 *                                   value. Not used if the first parameter is given as a closure
-	 * @param string          $label     Table column name that contains the pair's
-	 *                                   label. Not used if the first parameter is given as a closure
-	 * @param callable        $condition Function that will add `where`
-	 *                                   conditions to the query
-	 * @param callable        $format    Function will render each label
-	 * @param string          $order     SQL ordering
+	 * @param string|callable(Database): (false|array) $table     Database table name to use to get the
+	 *                                                            paired data from, or a closure function if providing a method
+	 * @param string                                   $value     Table column name that contains the pair's
+	 *                                                            value. Not used if the first parameter is given as a closure
+	 * @param string                                   $label     Table column name that contains the pair's
+	 *                                                            label. Not used if the first parameter is given as a closure
+	 * @param \Closure(Query): void                    $condition Function that will add `where`
+	 *                                                            conditions to the query
+	 * @param callable(array): string                  $format    Function will render each label
+	 * @param string                                   $order     SQL ordering
 	 *
 	 * @return ($table is null ? Options : $this)
 	 */
@@ -340,7 +342,7 @@ public function options($table = null, $value = null, $label = null, $condition
 	/**
 	 * Get a list of values that can be used for the options list in SearchPanes.
 	 *
-	 * @param SearchPaneOptions|callable $spInput SearchPaneOptions instance or a closure function if providing a method
+	 * @param SearchPaneOptions|callable(Database, DataTables\Editor): (array|bool) $spInput SearchPaneOptions instance or a closure function if providing a method
 	 *
 	 * @return ($spInput is null ? SearchPaneOptions|null : $this)
 	 */
@@ -367,7 +369,7 @@ public function searchPaneOptions($spInput = null)
 	/**
 	 * Get a list of values that can be used for the options list in SearchBuilder.
 	 *
-	 * @param SearchBuilderOptions|callable $sbInput SearchBuilderOptions instance or a closure function if providing a method
+	 * @param SearchBuilderOptions|callable(Database, DataTables\Editor): (Promise<IOption[]>|bool) $sbInput SearchBuilderOptions instance or a closure function if providing a method
 	 *
 	 * @return ($sbInput is null ? SearchBuilderOptions|null : $this)
 	 */
@@ -434,13 +436,13 @@ public function set($_ = null)
 	 * Editor has a number of formatters available with the {@see Format} class
 	 * which can be used directly with this method.
 	 *
-	 * @param callable|string $_    Value to set if using as a setter. Can be given as
-	 *                              a closure function or a string with a reference to a function that will
-	 *                              be called with call_user_func().
-	 * @param mixed           $opts Variable that is passed through to the get formatting
-	 *                              function - can be useful for passing through extra information such as
-	 *                              date formatting string, or a required flag. The actual options available
-	 *                              depend upon the formatter used.
+	 * @param callable(mixed, array, array): string $_    Value to set if using as a setter. Can be given as
+	 *                                                    a closure function or a string with a reference to a function that will
+	 *                                                    be called with call_user_func().
+	 * @param mixed                                 $opts Variable that is passed through to the get formatting
+	 *                                                    function - can be useful for passing through extra information such as
+	 *                                                    date formatting string, or a required flag. The actual options available
+	 *                                                    depend upon the formatter used.
 	 *
 	 * @return ($_ is null ? callable|string : $this) The set formatter if no parameter is given.
 	 */
@@ -457,8 +459,8 @@ public function setFormatter($_ = null, $opts = null)
 	 * Get / set a set value. If given, then this value is used to write to the
 	 * database regardless of what data is sent from the client-side.
 	 *
-	 * @param callable|string|number $_ Value to set, or no value to use as a
-	 *                                  getter
+	 * @param \Closure(): mixed|string|number $_ Value to set, or no value to use as a
+	 *                                           getter
 	 *
 	 * @return ($_ is null ? callable|string : $this) Value if used as a getter.
 	 */
@@ -492,13 +494,13 @@ public function upload($_ = null)
 	 * Editor has a number of validation available with the {@see Validate} class
 	 * which can be used directly with this method.
 	 *
-	 * @param callable|string $_    Value to set if using as the validation method.
-	 *                              Can be given as a closure function or a string with a reference to a
-	 *                              function that will be called with call_user_func().
-	 * @param mixed           $opts Variable that is passed through to the validation
-	 *                              function - can be useful for passing through extra information such as
-	 *                              date formatting string, or a required flag. The actual options available
-	 *                              depend upon the validation function used.
+	 * @param callable(mixed, array, $this, array): (true|string)|string $_    Value to set if using as the validation method.
+	 *                                                                         Can be given as a closure function or a string with a reference to a
+	 *                                                                         function that will be called with call_user_func().
+	 * @param mixed                                                      $opts Variable that is passed through to the validation
+	 *                                                                         function - can be useful for passing through extra information such as
+	 *                                                                         date formatting string, or a required flag. The actual options available
+	 *                                                                         depend upon the validation function used.
 	 *
 	 * @return ($_ is null ? array[] : $this) The validation method if no parameter is given.
 	 */
@@ -531,8 +533,8 @@ public function validator($_ = null, $opts = null)
 	 * simply provide a closure function that returns the value given to the
 	 * function. This is _not_ recommended.
 	 *
-	 * @param callable|false $xssFormatter XSS cleaner function, use `false` or
-	 *                                     `null` to disable XSS cleaning.
+	 * @param callable(mixed): string|false $xssFormatter XSS cleaner function, use `false` or
+	 *                                                    `null` to disable XSS cleaning.
 	 *
 	 * @return $this
 	 */
@@ -860,12 +862,12 @@ public function xssSafety($val)
 	 * Apply a formatter to data. The caller will decide what formatter to apply
 	 * (get or set).
 	 *
-	 * @param mixed    $val       Value to be formatted
-	 * @param array    $data      Full row data
-	 * @param callable $formatter Formatting function to be called
-	 * @param array    $opts      Array of options to be passed to the formatter
+	 * @param mixed                                 $val       Value to be formatted
+	 * @param array                                 $data      Full row data
+	 * @param callable(mixed, array, array): string $formatter Formatting function to be called
+	 * @param array                                 $opts      Array of options to be passed to the formatter
 	 *
-	 * @return mixed Formatted value
+	 * @return string Formatted value
 	 */
 	private function _format($val, $data, $formatter, $opts)
 	{
diff --git a/Editor/Join.php b/Editor/Join.php
index b6a1a4e..51ed470 100644
--- a/Editor/Join.php
+++ b/Editor/Join.php
@@ -14,6 +14,7 @@
 namespace DataTables\Editor;
 
 use DataTables;
+use DataTables\Database\Query;
 use DataTables\Editor;
 
 /**
@@ -404,9 +405,9 @@ public function type($_ = null)
 	/**
 	 * Set a validator for the array of data (not on a field basis).
 	 *
-	 * @param string   $fieldName Name of the field that any error should be shown
-	 *                            against on the client-side
-	 * @param callable $fn        Callback function for validation
+	 * @param string                                    $fieldName Name of the field that any error should be shown
+	 *                                                             against on the client-side
+	 * @param callable(Editor, string, string): ?string $fn        Callback function for validation
 	 *
 	 * @return $this
 	 */
@@ -429,9 +430,9 @@ public function validator($fieldName, $fn)
 	 * * Simple case: `where( field, value, operator )`
 	 * * Complex: `where( fn )`
 	 *
-	 * @param string|callable $key   Single field name or a closure function
-	 * @param string|string[] $value Single field value, or an array of values.
-	 * @param string          $op    Condition operator: <, >, = etc
+	 * @param string|\Closure(Query): void $key   Single field name or a closure function
+	 * @param string|string[]              $value Single field value, or an array of values.
+	 * @param string                       $op    Condition operator: <, >, = etc
 	 *
 	 * @return ($key is null ? string[] : $this) Where condition array.
 	 */
@@ -809,7 +810,7 @@ public function validate(&$errors, $editor, $data, $action)
 	private function _apply_where($query)
 	{
 		for ($i = 0; $i < count($this->_where); ++$i) {
-			if (is_callable($this->_where[$i])) {
+			if ($this->_where[$i] instanceof \Closure) {
 				$this->_where[$i]($query);
 			} else {
 				$query->where(
@@ -857,7 +858,7 @@ private function _insert($db, $parentId, $data)
 			// Note that `whereSet` is now deprecated
 			if ($this->_whereSet) {
 				for ($i = 0, $ien = count($this->_where); $i < $ien; ++$i) {
-					if (!is_callable($this->_where[$i])) {
+					if (!$this->_where[$i] instanceof \Closure) {
 						$stmt->set($this->_where[$i]['key'], $this->_where[$i]['value']);
 					}
 				}
@@ -971,7 +972,7 @@ private function _update_row($db, $parentId, $data)
 				// Is there any point in this? Is there any harm?
 				// Note that `whereSet` is now deprecated
 				if ($this->_whereSet) {
-					if (!is_callable($this->_where[$i])) {
+					if (!$this->_where[$i] instanceof \Closure) {
 						$set[$this->_where[$i]['key']] = $this->_where[$i]['value'];
 					}
 				}
diff --git a/Editor/Options.php b/Editor/Options.php
index efcbc95..800bb0a 100644
--- a/Editor/Options.php
+++ b/Editor/Options.php
@@ -15,6 +15,7 @@
 
 use DataTables;
 use DataTables\Database;
+use DataTables\Database\Query;
 
 /**
  * The Options class provides a convenient method of specifying where Editor
@@ -192,7 +193,7 @@ public function order($_ = null)
 	 * multiple database columns into a single string that is shown as the label
 	 * to the end user in the list of options.
 	 *
-	 * @param callable|null $_ Function to set, null to get current value
+	 * @param callable(array): string|null $_ Function to set, null to get current value
 	 *
 	 * @return ($_ is null ? callable : $this)
 	 */
@@ -231,7 +232,7 @@ public function value($_ = null)
 	 * Get / set the method to use for a WHERE condition if it is to be
 	 * applied to the query to get the options.
 	 *
-	 * @param callable|null $_ Function to set, null to get current value
+	 * @param \Closure(Query): void|null $_ Function to set, null to get current value
 	 *
 	 * @return ($_ is null ? callable : $this)
 	 */
diff --git a/Editor/SearchBuilderOptions.php b/Editor/SearchBuilderOptions.php
index e49c2dc..4552b1b 100644
--- a/Editor/SearchBuilderOptions.php
+++ b/Editor/SearchBuilderOptions.php
@@ -14,6 +14,7 @@
 namespace DataTables\Editor;
 
 use DataTables;
+use DataTables\Database\Query;
 
 /**
  * The Options class provides a convenient method of specifying where Editor
@@ -130,7 +131,7 @@ public function order($_ = null)
 	 * multiple database columns into a single string that is shown as the label
 	 * to the end user in the list of options.
 	 *
-	 * @param callable|null $_ Function to set, null to get current value
+	 * @param callable(string): string|null $_ Function to set, null to get current value
 	 *
 	 * @return ($_ is null ? callable : $this)
 	 */
@@ -169,7 +170,7 @@ public function value($_ = null)
 	 * Get / set the method to use for a WHERE condition if it is to be
 	 * applied to the query to get the options.
 	 *
-	 * @param callable|null $_ Function to set, null to get current value
+	 * @param \Closure(Query): void|null $_ Function to set, null to get current value
 	 *
 	 * @return ($_ is null ? callable : $this)
 	 */
@@ -211,7 +212,7 @@ public function leftJoin($table, $field1, $operator, $field2)
 	private function _get_where($query)
 	{
 		for ($i = 0; $i < count($this->_where); ++$i) {
-			if (is_callable($this->_where[$i])) {
+			if ($this->_where[$i] instanceof \Closure) {
 				$this->_where[$i]($query);
 			} else {
 				$query->where(
diff --git a/Editor/SearchPaneOptions.php b/Editor/SearchPaneOptions.php
index d728211..72270f8 100644
--- a/Editor/SearchPaneOptions.php
+++ b/Editor/SearchPaneOptions.php
@@ -14,6 +14,7 @@
 namespace DataTables\Editor;
 
 use DataTables;
+use DataTables\Database\Query;
 
 /**
  * The Options class provides a convenient method of specifying where Editor
@@ -130,7 +131,7 @@ public function order($_ = null)
 	 * multiple database columns into a single string that is shown as the label
 	 * to the end user in the list of options.
 	 *
-	 * @param callable|null $_ Function to set, null to get current value
+	 * @param callable(string): string|null $_ Function to set, null to get current value
 	 *
 	 * @return ($_ is null ? callable : $this)
 	 */
@@ -169,7 +170,7 @@ public function value($_ = null)
 	 * Get / set the method to use for a WHERE condition if it is to be
 	 * applied to the query to get the options.
 	 *
-	 * @param callable|null $_ Function to set, null to get current value
+	 * @param \Closure(Query): void|null $_ Function to set, null to get current value
 	 *
 	 * @return ($_ is null ? callable : $this)
 	 */
@@ -211,7 +212,7 @@ public function leftJoin($table, $field1, $operator, $field2)
 	private function _get_where($query)
 	{
 		for ($i = 0; $i < count($this->_where); ++$i) {
-			if (is_callable($this->_where[$i])) {
+			if ($this->_where[$i] instanceof \Closure) {
 				$this->_where[$i]($query);
 			} else {
 				$query->where(
diff --git a/Editor/Upload.php b/Editor/Upload.php
index d619cb9..f55c7e2 100644
--- a/Editor/Upload.php
+++ b/Editor/Upload.php
@@ -14,6 +14,7 @@
 namespace DataTables\Editor;
 
 use DataTables;
+use DataTables\Database\Query;
 
 /**
  * Upload class for Editor. This class provides the ability to easily specify
@@ -141,8 +142,8 @@ class Upload extends DataTables\Ext
 	/**
 	 * Upload instance constructor.
 	 *
-	 * @param string|callable $action Action to take on upload - this is applied
-	 *                                directly to {@see Upload->action()}.
+	 * @param string|\Closure(array, int): int $action Action to take on upload - this is applied
+	 *                                                 directly to {@see Upload->action()}.
 	 */
 	public function __construct($action = null)
 	{
@@ -170,7 +171,7 @@ public function __construct($action = null)
 	 *   typically involve writing it to the file system so it can be used
 	 *   later.
 	 *
-	 * @param string|callable $action Action to take - see description above.
+	 * @param string|\Closure(array, int): int $action Action to take - see description above.
 	 *
 	 * @return $this
 	 */
@@ -211,19 +212,19 @@ public function allowedExtensions($extn, $error = 'This file type cannot be uplo
 	 * you wish to store relational information about your file on the database
 	 * (this is generally recommended).
 	 *
-	 * @param string   $table  The name of the table where the file information
-	 *                         should be stored
-	 * @param string   $pkey   Primary key column name. The `Upload` class
-	 *                         requires that the database table have a single primary key so each
-	 *                         row can be uniquely identified.
-	 * @param array    $fields A list of the fields to be written to on upload.
-	 *                         The property names are the database columns and the values can be
-	 *                         defined by the constants of this class. The value can also be a
-	 *                         string or a closure function if you wish to send custom information
-	 *                         to the database.
-	 * @param callable $format Formatting function that can change the data obtained
-	 *                         from the database. Only gets a single parameter passed in - the
-	 *                         database row for the file that is read.
+	 * @param string                 $table  The name of the table where the file information
+	 *                                       should be stored
+	 * @param string                 $pkey   Primary key column name. The `Upload` class
+	 *                                       requires that the database table have a single primary key so each
+	 *                                       row can be uniquely identified.
+	 * @param array                  $fields A list of the fields to be written to on upload.
+	 *                                       The property names are the database columns and the values can be
+	 *                                       defined by the constants of this class. The value can also be a
+	 *                                       string or a closure function if you wish to send custom information
+	 *                                       to the database.
+	 * @param callable(array&): void $format Formatting function that can change the data obtained
+	 *                                       from the database. Only gets a single parameter passed in - the
+	 *                                       database row for the file that is read.
 	 *
 	 * @return $this
 	 */
@@ -241,11 +242,11 @@ public function db($table, $pkey, $fields, $format = null)
 	 * Set a callback function that is used to remove files which no longer have
 	 * a reference in a source table.
 	 *
-	 * @param callable $callback Function that will be executed on clean. It is
-	 *                           given an array of information from the database about the orphaned
-	 *                           rows, and can return true to indicate that the rows should be
-	 *                           removed from the database. Any other return value (including none)
-	 *                           will result in the records being retained.
+	 * @param callable(array): bool $callback Function that will be executed on clean. It is
+	 *                                        given an array of information from the database about the orphaned
+	 *                                        rows, and can return true to indicate that the rows should be
+	 *                                        removed from the database. Any other return value (including none)
+	 *                                        will result in the records being retained.
 	 *
 	 * @return $this
 	 */
@@ -281,9 +282,9 @@ public function mode($m)
 	 * added by calling this method multiple times - they will be executed in
 	 * sequence when a file has been uploaded.
 	 *
-	 * @param callable $fn Validation function. A PHP `$_FILES` parameter is
-	 *                     passed in for the uploaded file and the return is either a string
-	 *                     (validation failed and error message), or `null` (validation passed).
+	 * @param callable(array): ?string $fn Validation function. A PHP `$_FILES` parameter is
+	 *                                     passed in for the uploaded file and the return is either a string
+	 *                                     (validation failed and error message), or `null` (validation passed).
 	 *
 	 * @return $this
 	 */
@@ -300,7 +301,7 @@ public function validator($fn)
 	 * will be passed in a single argument, the `Query` object, to which
 	 * conditions can be added. Multiple calls to this method can be made.
 	 *
-	 * @param callable $fn Where function.
+	 * @param \Closure(Query): void $fn Where function.
 	 *
 	 * @return $this
 	 */