diff --git a/ext/pdo/pdo_dbh.stub.php b/ext/pdo/pdo_dbh.stub.php
index d25408db7e..9d37ad5497 100644
--- a/ext/pdo/pdo_dbh.stub.php
+++ b/ext/pdo/pdo_dbh.stub.php
@@ -6,48 +6,48 @@ class PDO
 {
     public function __construct(string $dsn, ?string $username = null, ?string $password = null, ?array $options = null) {}
 
-    /** @return bool */
-    public function beginTransaction() {}
+    /** @tentative-return-type */
+    public function beginTransaction(): bool {}
 
-    /** @return bool */
-    public function commit() {}
+    /** @tentative-return-type */
+    public function commit(): bool {}
 
-    /** @return string|null */
-    public function errorCode() {}
+    /** @tentative-return-type */
+    public function errorCode(): ?string {}
 
-    /** @return array */
-    public function errorInfo() {}
+    /** @tentative-return-type */
+    public function errorInfo(): array {}
 
-    /** @return int|false */
-    public function exec(string $statement) {}
+    /** @tentative-return-type */
+    public function exec(string $statement): int|false {}
 
-    /** @return bool|int|string|array|null */
-    public function getAttribute(int $attribute) {}
+    /** @tentative-return-type */
+    public function getAttribute(int $attribute): mixed {}
 
-    /** @return array */
-    public static function getAvailableDrivers() {}
+    /** @tentative-return-type */
+    public static function getAvailableDrivers(): array {}
 
-    /** @return bool */
-    public function inTransaction() {}
+    /** @tentative-return-type */
+    public function inTransaction(): bool {}
 
-    /** @return string|false */
-    public function lastInsertId(?string $name = null) {}
+    /** @tentative-return-type */
+    public function lastInsertId(?string $name = null): string|false {}
 
-    /** @return PDOStatement|false */
-    public function prepare(string $query, array $options = []) {}
+    /** @tentative-return-type */
+    public function prepare(string $query, array $options = []): PDOStatement|false {}
 
-    /** @return PDOStatement|false */
-    public function query(string $query, ?int $fetchMode = null, mixed ...$fetchModeArgs) {}
+    /** @tentative-return-type */
+    public function query(string $query, ?int $fetchMode = null, mixed ...$fetchModeArgs): PDOStatement|false {}
 
-    /** @return string|false */
-    public function quote(string $string, int $type = PDO::PARAM_STR) {}
+    /** @tentative-return-type */
+    public function quote(string $string, int $type = PDO::PARAM_STR): string|false {}
 
-    /** @return bool */
-    public function rollBack() {}
+    /** @tentative-return-type */
+    public function rollBack(): bool {}
 
     /**
      * @param array|int $value
-     * @return bool
+     * @tentative-return-type
      */
-    public function setAttribute(int $attribute, $value) {}
+    public function setAttribute(int $attribute, $value): bool {}
 }
diff --git a/ext/pdo/pdo_dbh_arginfo.h b/ext/pdo/pdo_dbh_arginfo.h
index a78807d688..b9916847d9 100644
--- a/ext/pdo/pdo_dbh_arginfo.h
+++ b/ext/pdo/pdo_dbh_arginfo.h
@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 779192c91fd281db6d2dc04143dd8656148ed789 */
+ * Stub hash: c0f18da92bca9f57b18e58fbc96e47b4195519a2 */
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO___construct, 0, 0, 1)
 	ZEND_ARG_TYPE_INFO(0, dsn, IS_STRING, 0)
@@ -8,50 +8,52 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO___construct, 0, 0, 1)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, options, IS_ARRAY, 1, "null")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_beginTransaction, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_beginTransaction, 0, 0, _IS_BOOL, 0)
 ZEND_END_ARG_INFO()
 
 #define arginfo_class_PDO_commit arginfo_class_PDO_beginTransaction
 
-#define arginfo_class_PDO_errorCode arginfo_class_PDO_beginTransaction
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_errorCode, 0, 0, IS_STRING, 1)
+ZEND_END_ARG_INFO()
 
-#define arginfo_class_PDO_errorInfo arginfo_class_PDO_beginTransaction
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_errorInfo, 0, 0, IS_ARRAY, 0)
+ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_exec, 0, 0, 1)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_PDO_exec, 0, 1, MAY_BE_LONG|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, statement, IS_STRING, 0)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_getAttribute, 0, 0, 1)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_getAttribute, 0, 1, IS_MIXED, 0)
 	ZEND_ARG_TYPE_INFO(0, attribute, IS_LONG, 0)
 ZEND_END_ARG_INFO()
 
-#define arginfo_class_PDO_getAvailableDrivers arginfo_class_PDO_beginTransaction
+#define arginfo_class_PDO_getAvailableDrivers arginfo_class_PDO_errorInfo
 
 #define arginfo_class_PDO_inTransaction arginfo_class_PDO_beginTransaction
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_lastInsertId, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_PDO_lastInsertId, 0, 0, MAY_BE_STRING|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, name, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_prepare, 0, 0, 1)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_OBJ_TYPE_MASK_EX(arginfo_class_PDO_prepare, 0, 1, PDOStatement, MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, query, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, options, IS_ARRAY, 0, "[]")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_query, 0, 0, 1)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_OBJ_TYPE_MASK_EX(arginfo_class_PDO_query, 0, 1, PDOStatement, MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, query, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, fetchMode, IS_LONG, 1, "null")
 	ZEND_ARG_VARIADIC_TYPE_INFO(0, fetchModeArgs, IS_MIXED, 0)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_quote, 0, 0, 1)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_PDO_quote, 0, 1, MAY_BE_STRING|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, string, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, type, IS_LONG, 0, "PDO::PARAM_STR")
 ZEND_END_ARG_INFO()
 
 #define arginfo_class_PDO_rollBack arginfo_class_PDO_beginTransaction
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_setAttribute, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_setAttribute, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, attribute, IS_LONG, 0)
 	ZEND_ARG_INFO(0, value)
 ZEND_END_ARG_INFO()
diff --git a/ext/pdo/pdo_stmt.stub.php b/ext/pdo/pdo_stmt.stub.php
index 166b8f2840..f90f1ed574 100644
--- a/ext/pdo/pdo_stmt.stub.php
+++ b/ext/pdo/pdo_stmt.stub.php
@@ -6,62 +6,63 @@ class PDOStatement implements IteratorAggregate
 {
     public string $queryString;
 
-    /** @return bool */
-    public function bindColumn(string|int $column, mixed &$var, int $type = PDO::PARAM_STR, int $maxLength = 0, mixed $driverOptions = null) {}
+    /** @tentative-return-type */
+    public function bindColumn(string|int $column, mixed &$var, int $type = PDO::PARAM_STR, int $maxLength = 0, mixed $driverOptions = null): bool {}
 
-    /** @return bool */
-    public function bindParam(string|int $param, mixed &$var, int $type = PDO::PARAM_STR, int $maxLength = 0, mixed $driverOptions = null) {}
+    /** @tentative-return-type */
+    public function bindParam(string|int $param, mixed &$var, int $type = PDO::PARAM_STR, int $maxLength = 0, mixed $driverOptions = null): bool {}
 
-    /** @return bool */
-    public function bindValue(string|int $param, mixed $value, int $type = PDO::PARAM_STR) {}
+    /** @tentative-return-type */
+    public function bindValue(string|int $param, mixed $value, int $type = PDO::PARAM_STR): bool {}
 
-    /** @return bool */
-    public function closeCursor() {}
+    /** @tentative-return-type */
+    public function closeCursor(): bool {}
 
-    /** @return int */
-    public function columnCount() {}
+    /** @tentative-return-type */
+    public function columnCount(): int {}
 
-    /** @return bool|null */
-    public function debugDumpParams() {}
+    /** @tentative-return-type */
+    public function debugDumpParams(): ?bool {}
 
-    /** @return string|null */
-    public function errorCode() {}
+    /** @tentative-return-type */
+    public function errorCode(): ?string {}
 
     /** @return array */
-    public function errorInfo() {}
+    /** @tentative-return-type */
+    public function errorInfo(): array {}
+
+    /** @tentative-return-type */
+    public function execute(?array $params = null): bool {}
+
+    /** @tentative-return-type */
+    public function fetch(int $mode = PDO::FETCH_DEFAULT, int $cursorOrientation = PDO::FETCH_ORI_NEXT, int $cursorOffset = 0): mixed {}
+
+    /** @tentative-return-type */
+    public function fetchAll(int $mode = PDO::FETCH_DEFAULT, mixed ...$args): array {}
+
+    /** @tentative-return-type */
+    public function fetchColumn(int $column = 0): mixed {}
+
+    /** @tentative-return-type */
+    public function fetchObject(?string $class = "stdClass", array $constructorArgs = []): object|false {}
+
+    /** @tentative-return-type */
+    public function getAttribute(int $name): mixed {}
+
+    /** @tentative-return-type */
+    public function getColumnMeta(int $column): array|false {}
+
+    /** @tentative-return-type */
+    public function nextRowset(): bool {}
+
+    /** @tentative-return-type */
+    public function rowCount(): int {}
+
+    /** @tentative-return-type */
+    public function setAttribute(int $attribute, mixed $value): bool {}
 
     /** @return bool */
-    public function execute(?array $params = null) {}
-
-    /** @return mixed */
-    public function fetch(int $mode = PDO::FETCH_DEFAULT, int $cursorOrientation = PDO::FETCH_ORI_NEXT, int $cursorOffset = 0) {}
-
-    /** @return array */
-    public function fetchAll(int $mode = PDO::FETCH_DEFAULT, mixed ...$args) {}
-
-    /** @return mixed */
-    public function fetchColumn(int $column = 0) {}
-
-    /** @return object|false */
-    public function fetchObject(?string $class = "stdClass", array $constructorArgs = []) {}
-
-    /** @return mixed */
-    public function getAttribute(int $name) {}
-
-    /** @return array|false */
-    public function getColumnMeta(int $column) {}
-
-    /** @return bool */
-    public function nextRowset() {}
-
-    /** @return int */
-    public function rowCount() {}
-
-    /** @return bool */
-    public function setAttribute(int $attribute, mixed $value) {}
-
-    /** @return bool */
-    public function setFetchMode(int $mode, mixed ...$args) {}
+    public function setFetchMode(int $mode, mixed ...$args) {} // TODO make return type void
 
     public function getIterator(): Iterator {}
 }
diff --git a/ext/pdo/pdo_stmt_arginfo.h b/ext/pdo/pdo_stmt_arginfo.h
index e93e5ad1df..185e7c29dd 100644
--- a/ext/pdo/pdo_stmt_arginfo.h
+++ b/ext/pdo/pdo_stmt_arginfo.h
@@ -1,7 +1,7 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 95416f12e78609bbb9ed2e70835180654f8e78c8 */
+ * Stub hash: 406aff009e4091eaac0937aaf0801c934a0f3f71 */
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_bindColumn, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_bindColumn, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_MASK(0, column, MAY_BE_STRING|MAY_BE_LONG, NULL)
 	ZEND_ARG_TYPE_INFO(1, var, IS_MIXED, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, type, IS_LONG, 0, "PDO::PARAM_STR")
@@ -9,7 +9,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_bindColumn, 0, 0, 2)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, driverOptions, IS_MIXED, 0, "null")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_bindParam, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_bindParam, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_MASK(0, param, MAY_BE_STRING|MAY_BE_LONG, NULL)
 	ZEND_ARG_TYPE_INFO(1, var, IS_MIXED, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, type, IS_LONG, 0, "PDO::PARAM_STR")
@@ -17,60 +17,64 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_bindParam, 0, 0, 2)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, driverOptions, IS_MIXED, 0, "null")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_bindValue, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_bindValue, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_MASK(0, param, MAY_BE_STRING|MAY_BE_LONG, NULL)
 	ZEND_ARG_TYPE_INFO(0, value, IS_MIXED, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, type, IS_LONG, 0, "PDO::PARAM_STR")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_closeCursor, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_closeCursor, 0, 0, _IS_BOOL, 0)
 ZEND_END_ARG_INFO()
 
-#define arginfo_class_PDOStatement_columnCount arginfo_class_PDOStatement_closeCursor
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_columnCount, 0, 0, IS_LONG, 0)
+ZEND_END_ARG_INFO()
 
-#define arginfo_class_PDOStatement_debugDumpParams arginfo_class_PDOStatement_closeCursor
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_debugDumpParams, 0, 0, _IS_BOOL, 1)
+ZEND_END_ARG_INFO()
 
-#define arginfo_class_PDOStatement_errorCode arginfo_class_PDOStatement_closeCursor
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_errorCode, 0, 0, IS_STRING, 1)
+ZEND_END_ARG_INFO()
 
-#define arginfo_class_PDOStatement_errorInfo arginfo_class_PDOStatement_closeCursor
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_errorInfo, 0, 0, IS_ARRAY, 0)
+ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_execute, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_execute, 0, 0, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, params, IS_ARRAY, 1, "null")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_fetch, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_fetch, 0, 0, IS_MIXED, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, mode, IS_LONG, 0, "PDO::FETCH_DEFAULT")
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, cursorOrientation, IS_LONG, 0, "PDO::FETCH_ORI_NEXT")
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, cursorOffset, IS_LONG, 0, "0")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_fetchAll, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_fetchAll, 0, 0, IS_ARRAY, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, mode, IS_LONG, 0, "PDO::FETCH_DEFAULT")
 	ZEND_ARG_VARIADIC_TYPE_INFO(0, args, IS_MIXED, 0)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_fetchColumn, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_fetchColumn, 0, 0, IS_MIXED, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, column, IS_LONG, 0, "0")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_fetchObject, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_PDOStatement_fetchObject, 0, 0, MAY_BE_OBJECT|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, class, IS_STRING, 1, "\"stdClass\"")
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, constructorArgs, IS_ARRAY, 0, "[]")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_getAttribute, 0, 0, 1)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_getAttribute, 0, 1, IS_MIXED, 0)
 	ZEND_ARG_TYPE_INFO(0, name, IS_LONG, 0)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_getColumnMeta, 0, 0, 1)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_PDOStatement_getColumnMeta, 0, 1, MAY_BE_ARRAY|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, column, IS_LONG, 0)
 ZEND_END_ARG_INFO()
 
 #define arginfo_class_PDOStatement_nextRowset arginfo_class_PDOStatement_closeCursor
 
-#define arginfo_class_PDOStatement_rowCount arginfo_class_PDOStatement_closeCursor
+#define arginfo_class_PDOStatement_rowCount arginfo_class_PDOStatement_columnCount
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDOStatement_setAttribute, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDOStatement_setAttribute, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, attribute, IS_LONG, 0)
 	ZEND_ARG_TYPE_INFO(0, value, IS_MIXED, 0)
 ZEND_END_ARG_INFO()
diff --git a/ext/pdo/tests/bug_47769.phpt b/ext/pdo/tests/bug_47769.phpt
index daac15574a..4e2253148c 100644
--- a/ext/pdo/tests/bug_47769.phpt
+++ b/ext/pdo/tests/bug_47769.phpt
@@ -17,10 +17,12 @@ class test extends PDO
         echo "this is a private method.\n";
     }
 
-    public function quote($str, $paramtype = NULL) {
+    public function quote($str, $paramtype = NULL): string|false {
         $this->isProtected();
         $this->isPrivate();
         print $str ."\n";
+
+        return $str;
     }
 }
 
diff --git a/ext/pdo/tests/pdo_023.phpt b/ext/pdo/tests/pdo_023.phpt
index ee38f98cac..98948fcac6 100644
--- a/ext/pdo/tests/pdo_023.phpt
+++ b/ext/pdo/tests/pdo_023.phpt
@@ -47,7 +47,7 @@ class PDODatabaseX extends PDO
         $this->test2 = 22;
     }
 
-    function query($sql, ...$rest)
+    function query($sql, ...$rest): PDOStatement|false
     {
         echo __METHOD__ . "()\n";
         $stmt = parent::prepare($sql, array(PDO::ATTR_STATEMENT_CLASS=>array('PDOStatementx')));
diff --git a/ext/pdo/tests/pdo_026.phpt b/ext/pdo/tests/pdo_026.phpt
index 23d599e847..a169926a30 100644
--- a/ext/pdo/tests/pdo_026.phpt
+++ b/ext/pdo/tests/pdo_026.phpt
@@ -42,7 +42,7 @@ class PDODatabase extends PDO
         echo __METHOD__ . "()\n";
     }
 
-    function query($sql, ...$rest)
+    function query($sql, ...$rest): PDOStatement|false
     {
         echo __METHOD__ . "()\n";
         $stmt = $this->prepare($sql, array(PDO::ATTR_STATEMENT_CLASS=>array('PDOStatementx', array($this))));
diff --git a/ext/pdo/tests/pdo_029.phpt b/ext/pdo/tests/pdo_029.phpt
index 4eaf922bfd..b79cd7ec49 100644
--- a/ext/pdo/tests/pdo_029.phpt
+++ b/ext/pdo/tests/pdo_029.phpt
@@ -34,10 +34,10 @@ class PDOStatementX extends PDOStatement
         echo __METHOD__ . "()\n";
     }
 
-    function execute($params = array())
+    function execute($params = array()): bool
     {
         echo __METHOD__ . "()\n";
-        parent::execute();
+        return parent::execute();
     }
 }
 
@@ -48,7 +48,7 @@ class PDODatabase extends PDO
         echo __METHOD__ . "()\n";
     }
 
-    function query($sql, ...$rest)
+    function query($sql, ...$rest): PDOStatement|false
     {
         echo __METHOD__ . "()\n";
         $stmt = $this->prepare($sql, array(PDO::ATTR_STATEMENT_CLASS=>array('PDOStatementx', array($this))));
diff --git a/ext/pdo/tests/pdo_030.phpt b/ext/pdo/tests/pdo_030.phpt
index e21047d630..c71d96171f 100644
--- a/ext/pdo/tests/pdo_030.phpt
+++ b/ext/pdo/tests/pdo_030.phpt
@@ -35,7 +35,7 @@ class PDOStatementX extends PDOStatement
         echo __METHOD__ . "()\n";
     }
 
-    function execute($params = array())
+    function execute($params = array()): bool
     {
         echo __METHOD__ . "()\n";
         parent::execute();
@@ -49,7 +49,7 @@ class PDODatabase extends PDO
         echo __METHOD__ . "()\n";
     }
 
-    function query($sql, ...$rest)
+    function query($sql, ...$rest): PDOStatement|false
     {
         echo __METHOD__ . "()\n";
         return parent::query($sql);
diff --git a/ext/pdo_mysql/tests/pdo_mysql_attr_statement_class.phpt b/ext/pdo_mysql/tests/pdo_mysql_attr_statement_class.phpt
index 4bbf639939..9ca2e3a6b0 100644
--- a/ext/pdo_mysql/tests/pdo_mysql_attr_statement_class.phpt
+++ b/ext/pdo_mysql/tests/pdo_mysql_attr_statement_class.phpt
@@ -96,8 +96,8 @@ $db = MySQLPDOTest::factory();
     $stmt = $db->query('SELECT id, label FROM test ORDER BY id ASC LIMIT 2');
 
     class mystatement5 extends mystatement4 {
-        public function fetchAll($fetch_style = 1, ...$fetch_args) {
-            return "no data :)";
+        public function fetchAll($fetch_style = 1, ...$fetch_args): array {
+            return [];
         }
     }
 
@@ -146,7 +146,8 @@ mystatement4
 string(6) "param1"
 mystatement5
 string(12) "mystatement5"
-string(10) "no data :)"
+array(0) {
+}
 array(1) {
   [0]=>
   array(4) {
diff --git a/ext/pdo_mysql/tests/pdo_mysql_subclass.phpt b/ext/pdo_mysql/tests/pdo_mysql_subclass.phpt
index d79de14862..8a2824f502 100644
--- a/ext/pdo_mysql/tests/pdo_mysql_subclass.phpt
+++ b/ext/pdo_mysql/tests/pdo_mysql_subclass.phpt
@@ -19,12 +19,12 @@ MySQLPDOTest::skip();
                 return call_user_func_array(array($this, 'parent::__construct'), func_get_args());
             }
 
-            public function exec($statement) {
+            public function exec($statement): int|false {
                 $this->protocol();
                 return parent::exec($statement);
             }
 
-            public function query(...$args) {
+            public function query(...$args): PDOStatement|false {
                 $this->protocol();
                 return parent::query(...$args);
             }
diff --git a/ext/pdo_pgsql/pgsql_driver.stub.php b/ext/pdo_pgsql/pgsql_driver.stub.php
index e6d3695373..6daa55c7b8 100644
--- a/ext/pdo_pgsql/pgsql_driver.stub.php
+++ b/ext/pdo_pgsql/pgsql_driver.stub.php
@@ -4,30 +4,30 @@
 
 // These are extension methods for PDO. This is not a real class.
 class PDO_PGSql_Ext {
-    /** @return bool */
-    public function pgsqlCopyFromArray(string $tableName, array $rows, string $separator = "\t", string $nullAs = "\\\\N", ?string $fields = null) {}
+    /** @tentative-return-type */
+    public function pgsqlCopyFromArray(string $tableName, array $rows, string $separator = "\t", string $nullAs = "\\\\N", ?string $fields = null): bool {}
 
-    /** @return bool */
-    public function pgsqlCopyFromFile(string $tableName, string $filename, string $separator = "\t", string $nullAs = "\\\\N", ?string $fields = null) {}
+    /** @tentative-return-type */
+    public function pgsqlCopyFromFile(string $tableName, string $filename, string $separator = "\t", string $nullAs = "\\\\N", ?string $fields = null): bool {}
 
-    /** @return array|false */
-    public function pgsqlCopyToArray(string $tableName, string $separator = "\t", string $nullAs = "\\\\N", ?string $fields = null) {}
+    /** @tentative-return-type */
+    public function pgsqlCopyToArray(string $tableName, string $separator = "\t", string $nullAs = "\\\\N", ?string $fields = null): array|false {}
 
-    /** @return bool */
-    public function pgsqlCopyToFile(string $tableName, string $filename, string $separator = "\t", string $nullAs = "\\\\N", ?string $fields = null) {}
+    /** @tentative-return-type */
+    public function pgsqlCopyToFile(string $tableName, string $filename, string $separator = "\t", string $nullAs = "\\\\N", ?string $fields = null): bool {}
 
-    /** @return string|false */
-    public function pgsqlLOBCreate() {}
+    /** @tentative-return-type */
+    public function pgsqlLOBCreate(): string|false {}
 
     /** @return resource|false */
     public function pgsqlLOBOpen(string $oid, string $mode = "rb") {}
 
-    /** @return bool */
-    public function pgsqlLOBUnlink(string $oid) {}
+    /** @tentative-return-type */
+    public function pgsqlLOBUnlink(string $oid): bool {}
 
-    /** @return array|false */
-    public function pgsqlGetNotify(int $fetchMode = PDO::FETCH_USE_DEFAULT, int $timeoutMilliseconds = 0) {}
+    /** @tentative-return-type */
+    public function pgsqlGetNotify(int $fetchMode = PDO::FETCH_USE_DEFAULT, int $timeoutMilliseconds = 0): array|false {}
 
-    /** @return int */
-    public function pgsqlGetPid() {}
+    /** @tentative-return-type */
+    public function pgsqlGetPid(): int {}
 }
diff --git a/ext/pdo_pgsql/pgsql_driver_arginfo.h b/ext/pdo_pgsql/pgsql_driver_arginfo.h
index d8d33450af..a3ec5196fa 100644
--- a/ext/pdo_pgsql/pgsql_driver_arginfo.h
+++ b/ext/pdo_pgsql/pgsql_driver_arginfo.h
@@ -1,7 +1,7 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 82be78f03c363afd795c59bcbb061ef0b2f9d08c */
+ * Stub hash: 5dfd421cf9ba9eb043c4b4f3c9b9c09c81cc3ccb */
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlCopyFromArray, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlCopyFromArray, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, tableName, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, rows, IS_ARRAY, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, separator, IS_STRING, 0, "\"\\t\"")
@@ -9,7 +9,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlCopyFromArray, 0, 0, 2)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, fields, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlCopyFromFile, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlCopyFromFile, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, tableName, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, filename, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, separator, IS_STRING, 0, "\"\\t\"")
@@ -17,7 +17,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlCopyFromFile, 0, 0, 2)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, fields, IS_STRING, 1, "null")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlCopyToArray, 0, 0, 1)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_PDO_PGSql_Ext_pgsqlCopyToArray, 0, 1, MAY_BE_ARRAY|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO(0, tableName, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, separator, IS_STRING, 0, "\"\\t\"")
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, nullAs, IS_STRING, 0, "\"\\\\\\\\N\"")
@@ -26,7 +26,7 @@ ZEND_END_ARG_INFO()
 
 #define arginfo_class_PDO_PGSql_Ext_pgsqlCopyToFile arginfo_class_PDO_PGSql_Ext_pgsqlCopyFromFile
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlLOBCreate, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_PDO_PGSql_Ext_pgsqlLOBCreate, 0, 0, MAY_BE_STRING|MAY_BE_FALSE)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlLOBOpen, 0, 0, 1)
@@ -34,16 +34,17 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlLOBOpen, 0, 0, 1)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, mode, IS_STRING, 0, "\"rb\"")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlLOBUnlink, 0, 0, 1)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlLOBUnlink, 0, 1, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, oid, IS_STRING, 0)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlGetNotify, 0, 0, 0)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_PDO_PGSql_Ext_pgsqlGetNotify, 0, 0, MAY_BE_ARRAY|MAY_BE_FALSE)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, fetchMode, IS_LONG, 0, "PDO::FETCH_USE_DEFAULT")
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, timeoutMilliseconds, IS_LONG, 0, "0")
 ZEND_END_ARG_INFO()
 
-#define arginfo_class_PDO_PGSql_Ext_pgsqlGetPid arginfo_class_PDO_PGSql_Ext_pgsqlLOBCreate
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_PGSql_Ext_pgsqlGetPid, 0, 0, IS_LONG, 0)
+ZEND_END_ARG_INFO()
 
 
 ZEND_METHOD(PDO_PGSql_Ext, pgsqlCopyFromArray);
diff --git a/ext/pdo_sqlite/sqlite_driver.stub.php b/ext/pdo_sqlite/sqlite_driver.stub.php
index fc827cd381..58fb41c9b9 100644
--- a/ext/pdo_sqlite/sqlite_driver.stub.php
+++ b/ext/pdo_sqlite/sqlite_driver.stub.php
@@ -4,12 +4,12 @@
 
 // These are extension methods for PDO. This is not a real class.
 class PDO_SQLite_Ext {
-    /** @return bool */
-    public function sqliteCreateFunction(string $name, callable $callback, int $numArgs = -1, int $flags = 0) {}
+    /** @tentative-return-type */
+    public function sqliteCreateFunction(string $name, callable $callback, int $numArgs = -1, int $flags = 0): bool {}
 
-    /** @return bool */
-    public function sqliteCreateAggregate(string $name, callable $step, callable $finalize, int $numArgs = -1) {}
+    /** @tentative-return-type */
+    public function sqliteCreateAggregate(string $name, callable $step, callable $finalize, int $numArgs = -1): bool {}
 
-    /** @return bool */
-    public function sqliteCreateCollation(string $name, callable $callback) {}
+    /** @tentative-return-type */
+    public function sqliteCreateCollation(string $name, callable $callback): bool {}
 }
diff --git a/ext/pdo_sqlite/sqlite_driver_arginfo.h b/ext/pdo_sqlite/sqlite_driver_arginfo.h
index 370f3d1315..2b9b1aea1e 100644
--- a/ext/pdo_sqlite/sqlite_driver_arginfo.h
+++ b/ext/pdo_sqlite/sqlite_driver_arginfo.h
@@ -1,21 +1,21 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 49737f1a08f0b1b66e326b7d06e316105202d27d */
+ * Stub hash: 8cc3c173f5a442ab80f240a568489b023aabd7ef */
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_SQLite_Ext_sqliteCreateFunction, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_SQLite_Ext_sqliteCreateFunction, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, name, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, callback, IS_CALLABLE, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, numArgs, IS_LONG, 0, "-1")
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, flags, IS_LONG, 0, "0")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_SQLite_Ext_sqliteCreateAggregate, 0, 0, 3)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_SQLite_Ext_sqliteCreateAggregate, 0, 3, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, name, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, step, IS_CALLABLE, 0)
 	ZEND_ARG_TYPE_INFO(0, finalize, IS_CALLABLE, 0)
 	ZEND_ARG_TYPE_INFO_WITH_DEFAULT_VALUE(0, numArgs, IS_LONG, 0, "-1")
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_PDO_SQLite_Ext_sqliteCreateCollation, 0, 0, 2)
+ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_PDO_SQLite_Ext_sqliteCreateCollation, 0, 2, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, name, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, callback, IS_CALLABLE, 0)
 ZEND_END_ARG_INFO()