diff --git a/ext/pdo/tests/pdo_017.phpt b/ext/pdo/tests/pdo_017.phpt
index bc514bff2c32b..d24aff1c15f32 100644
--- a/ext/pdo/tests/pdo_017.phpt
+++ b/ext/pdo/tests/pdo_017.phpt
@@ -8,7 +8,6 @@ $dir = getenv('REDIR_TEST_DIR');
 if (false == $dir) die('skip no driver');
 require_once $dir . 'pdo_test.inc';
 PDOTest::skip();
-if (str_starts_with(getenv('PDOTEST_DSN'), "firebird")) die('xfail firebird driver does not behave as expected');
 
 $db = PDOTest::factory();
 try {
diff --git a/ext/pdo_firebird/firebird_driver.c b/ext/pdo_firebird/firebird_driver.c
index bb9eb29ee9166..8b4572970a23f 100644
--- a/ext/pdo_firebird/firebird_driver.c
+++ b/ext/pdo_firebird/firebird_driver.c
@@ -33,6 +33,7 @@
 
 static int php_firebird_alloc_prepare_stmt(pdo_dbh_t*, const zend_string*, XSQLDA*, isc_stmt_handle*,
 	HashTable*);
+static bool php_firebird_rollback_transaction(pdo_dbh_t *dbh);
 
 const char CHR_LETTER = 1;
 const char CHR_DIGIT = 2;
@@ -526,17 +527,14 @@ static void firebird_handle_closer(pdo_dbh_t *dbh) /* {{{ */
 {
 	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
 
-	if (dbh->in_txn) {
+	if (H->tr) {
 		if (dbh->auto_commit) {
-			if (isc_commit_transaction(H->isc_status, &H->tr)) {
-				php_firebird_error(dbh);
-			}
+			php_firebird_commit_transaction(dbh, /* release */ false);
 		} else {
-			if (isc_rollback_transaction(H->isc_status, &H->tr)) {
-				php_firebird_error(dbh);
-			}
+			php_firebird_rollback_transaction(dbh);
 		}
 	}
+	H->in_manually_txn = 0;
 
 	if (isc_detach_database(H->isc_status, &H->db)) {
 		php_firebird_error(dbh);
@@ -702,9 +700,10 @@ static zend_long firebird_handle_doer(pdo_dbh_t *dbh, const zend_string *sql) /*
 		}
 	}
 
-	/* commit if we're in auto_commit mode */
-	if (dbh->auto_commit && isc_commit_retaining(H->isc_status, &H->tr)) {
-		php_firebird_error(dbh);
+	if (dbh->auto_commit && !H->in_manually_txn) {
+		if (!php_firebird_commit_transaction(dbh, /* retain */ true)) {
+			ret = -1;
+		}
 	}
 
 free_statement:
@@ -756,8 +755,8 @@ static zend_string* firebird_handle_quoter(pdo_dbh_t *dbh, const zend_string *un
 }
 /* }}} */
 
-/* called by PDO to start a transaction */
-static bool firebird_handle_begin(pdo_dbh_t *dbh) /* {{{ */
+/* php_firebird_begin_transaction */
+static bool php_firebird_begin_transaction(pdo_dbh_t *dbh) /* {{{ */
 {
 	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
 	char tpb[8] = { isc_tpb_version3 }, *ptpb = tpb+1;
@@ -809,12 +808,84 @@ static bool firebird_handle_begin(pdo_dbh_t *dbh) /* {{{ */
 }
 /* }}} */
 
+/* called by PDO to start a transaction */
+static bool firebird_handle_manually_begin(pdo_dbh_t *dbh) /* {{{ */
+{
+	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
+
+	/**
+	 * If in autocommit mode and in transaction, we will need to close the transaction once.
+	 */
+	if (dbh->auto_commit && H->tr) {
+		if (!php_firebird_commit_transaction(dbh, /* release */ false)) {
+			return false;
+		}
+	}
+
+	if (!php_firebird_begin_transaction(dbh)) {
+		return false;
+	}
+	H->in_manually_txn = 1;
+	return true;
+}
+/* }}} */
+
+/* php_firebird_commit_transaction */
+bool php_firebird_commit_transaction(pdo_dbh_t *dbh, bool retain) /* {{{ */
+{
+	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
+
+	/**
+	 * `retaining` keeps the transaction open without closing it.
+	 *
+	 * firebird needs to always have a transaction open to emulate autocommit mode,
+	 * and in autocommit mode it keeps the transaction open.
+	 *
+	 * Same as close and then begin again, but use retain to save overhead.
+	 */
+	if (retain) {
+		if (isc_commit_retaining(H->isc_status, &H->tr)) {
+			php_firebird_error(dbh);
+			return false;
+		}
+	} else {
+		if (isc_commit_transaction(H->isc_status, &H->tr)) {
+			php_firebird_error(dbh);
+			return false;
+		}
+	}
+	return true;
+}
+/* }}} */
+
 /* called by PDO to commit a transaction */
-static bool firebird_handle_commit(pdo_dbh_t *dbh) /* {{{ */
+static bool firebird_handle_manually_commit(pdo_dbh_t *dbh) /* {{{ */
+{
+	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
+	if (!php_firebird_commit_transaction(dbh, /*release*/ false)) {
+		return false;
+	}
+
+	/**
+	 * If in autocommit mode, begin the transaction again
+	 * Reopen instead of retain because isolation level may change
+	 */
+	if (dbh->auto_commit) {
+		if (!php_firebird_begin_transaction(dbh)) {
+			return false;
+		}
+	}
+	H->in_manually_txn = 0;
+	return true;
+}
+/* }}} */
+
+/* php_firebird_rollback_transaction */
+static bool php_firebird_rollback_transaction(pdo_dbh_t *dbh) /* {{{ */
 {
 	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
 
-	if (isc_commit_transaction(H->isc_status, &H->tr)) {
+	if (isc_rollback_transaction(H->isc_status, &H->tr)) {
 		php_firebird_error(dbh);
 		return false;
 	}
@@ -823,14 +894,24 @@ static bool firebird_handle_commit(pdo_dbh_t *dbh) /* {{{ */
 /* }}} */
 
 /* called by PDO to rollback a transaction */
-static bool firebird_handle_rollback(pdo_dbh_t *dbh) /* {{{ */
+static bool firebird_handle_manually_rollback(pdo_dbh_t *dbh) /* {{{ */
 {
 	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
 
-	if (isc_rollback_transaction(H->isc_status, &H->tr)) {
-		php_firebird_error(dbh);
+	if (!php_firebird_rollback_transaction(dbh)) {
 		return false;
 	}
+
+	/**
+	 * If in autocommit mode, begin the transaction again
+	 * Reopen instead of retain because isolation level may change
+	 */
+	if (dbh->auto_commit) {
+		if (!php_firebird_begin_transaction(dbh)) {
+			return false;
+		}
+	}
+	H->in_manually_txn = 0;
 	return true;
 }
 /* }}} */
@@ -848,16 +929,6 @@ static int php_firebird_alloc_prepare_stmt(pdo_dbh_t *dbh, const zend_string *sq
 		return 0;
 	}
 
-	/* start a new transaction implicitly if auto_commit is enabled and no transaction is open */
-	if (dbh->auto_commit && !dbh->in_txn) {
-		/* dbh->transaction_flags = PDO_TRANS_READ_UNCOMMITTED; */
-
-		if (!firebird_handle_begin(dbh)) {
-			return 0;
-		}
-		dbh->in_txn = true;
-	}
-
 	/* allocate the statement */
 	if (isc_dsql_allocate_statement(H->isc_status, &H->db, s)) {
 		php_firebird_error(dbh);
@@ -898,21 +969,34 @@ static bool pdo_firebird_set_attribute(pdo_dbh_t *dbh, zend_long attr, zval *val
 					return false;
 				}
 
+				if (H->in_manually_txn) {
+					/* change auto commit mode with an open transaction is illegal, because
+						we won't know what to do with it */
+					pdo_raise_impl_error(dbh, NULL, "HY000", "Cannot change autocommit mode while a transaction is already open");
+					return false;
+				}
+
 				/* ignore if the new value equals the old one */
 				if (dbh->auto_commit ^ bval) {
-					if (dbh->in_txn) {
-						if (bval) {
-							/* turning on auto_commit with an open transaction is illegal, because
-							   we won't know what to do with it */
-							const char *msg = "Cannot enable auto-commit while a transaction is already open";
-							php_firebird_error_with_info(dbh, "HY000", strlen("HY000"), msg, strlen(msg));
-							return false;
-						} else {
-							/* close the transaction */
-							if (!firebird_handle_commit(dbh)) {
-								break;
+					if (bval) {
+						/* change to auto commit mode.
+						 * If the transaction is not started, start it.
+						 * However, this is a fallback since such a situation usually does not occur.
+						 */
+						if (!H->tr) {
+							if (!php_firebird_begin_transaction(dbh)) {
+								return false;
+							}
+						}
+					} else {
+						/* change to not auto commit mode.
+						 * close the transaction if exists.
+						 * However, this is a fallback since such a situation usually does not occur.
+						 */
+						if (H->tr) {
+							if (!php_firebird_commit_transaction(dbh, /* release */ false)) {
+								return false;
 							}
-							dbh->in_txn = false;
 						}
 					}
 					dbh->auto_commit = bval;
@@ -1058,14 +1142,27 @@ static void pdo_firebird_fetch_error_func(pdo_dbh_t *dbh, pdo_stmt_t *stmt, zval
 }
 /* }}} */
 
+/* {{{ firebird_in_manually_transaction */
+static bool pdo_firebird_in_manually_transaction(pdo_dbh_t *dbh)
+{
+	/**
+	 * we can tell if a transaction exists now by checking H->tr,
+	 * but which will always be true in autocommit mode.
+	 * So this function checks if there is currently a "manually begun transaction".
+	 */
+	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
+	return H->in_manually_txn;
+}
+/* }}} */
+
 static const struct pdo_dbh_methods firebird_methods = { /* {{{ */
 	firebird_handle_closer,
 	firebird_handle_preparer,
 	firebird_handle_doer,
 	firebird_handle_quoter,
-	firebird_handle_begin,
-	firebird_handle_commit,
-	firebird_handle_rollback,
+	firebird_handle_manually_begin,
+	firebird_handle_manually_commit,
+	firebird_handle_manually_rollback,
 	pdo_firebird_set_attribute,
 	NULL, /* last_id not supported */
 	pdo_firebird_fetch_error_func,
@@ -1073,7 +1170,7 @@ static const struct pdo_dbh_methods firebird_methods = { /* {{{ */
 	NULL, /* check_liveness */
 	NULL, /* get driver methods */
 	NULL, /* request shutdown */
-	NULL, /* in transaction, use PDO's internal tracking mechanism */
+	pdo_firebird_in_manually_transaction,
 	NULL /* get gc */
 };
 /* }}} */
@@ -1154,6 +1251,11 @@ static int pdo_firebird_handle_factory(pdo_dbh_t *dbh, zval *driver_options) /*
 				"HY000", H->isc_status[1], errmsg);
 	}
 
+	H->in_manually_txn = 0;
+	if (dbh->auto_commit && !H->tr) {
+		ret = php_firebird_begin_transaction(dbh);
+	}
+
 	if (!ret) {
 		firebird_handle_closer(dbh);
 	}
diff --git a/ext/pdo_firebird/firebird_statement.c b/ext/pdo_firebird/firebird_statement.c
index bc973171b2f61..000c74d6dda08 100644
--- a/ext/pdo_firebird/firebird_statement.c
+++ b/ext/pdo_firebird/firebird_statement.c
@@ -180,8 +180,7 @@ static int pdo_firebird_stmt_execute(pdo_stmt_t *stmt) /* {{{ */
 				;
 		}
 
-		/* commit? */
-		if (stmt->dbh->auto_commit && isc_commit_retaining(H->isc_status, &H->tr)) {
+		if (stmt->dbh->auto_commit && !S->H->in_manually_txn && !php_firebird_commit_transaction(stmt->dbh, /* retain */ true)) {
 			break;
 		}
 
diff --git a/ext/pdo_firebird/php_pdo_firebird_int.h b/ext/pdo_firebird/php_pdo_firebird_int.h
index c7a0087ed6d9f..af598eae98ad9 100644
--- a/ext/pdo_firebird/php_pdo_firebird_int.h
+++ b/ext/pdo_firebird/php_pdo_firebird_int.h
@@ -66,7 +66,6 @@ typedef struct {
 } pdo_firebird_error_info;
 
 typedef struct {
-
 	/* the result of the last API call */
 	ISC_STATUS isc_status[20];
 
@@ -75,6 +74,7 @@ typedef struct {
 
 	/* the transaction handle */
 	isc_tr_handle tr;
+	bool in_manually_txn;
 
 	/* date and time format strings, can be set by the set_attribute method */
 	char *date_format;
@@ -93,7 +93,6 @@ typedef struct {
 
 
 typedef struct {
-
 	/* the link that owns this statement */
 	pdo_firebird_db_handle *H;
 
@@ -122,7 +121,6 @@ typedef struct {
 
 	/* the output SQLDA */
 	XSQLDA out_sqlda; /* last member */
-
 } pdo_firebird_stmt;
 
 extern const pdo_driver_t pdo_firebird_driver;
@@ -136,6 +134,8 @@ extern void php_firebird_set_error(pdo_dbh_t *dbh, pdo_stmt_t *stmt, const char
 #define php_firebird_error_with_info(d,e,el,m,ml) php_firebird_set_error(d, NULL, e, el, m, ml)
 #define php_firebird_error_stmt_with_info(s,e,el,m,ml) php_firebird_set_error(s->dbh, s, e, el, m, ml)
 
+extern bool php_firebird_commit_transaction(pdo_dbh_t *dbh, bool retain);
+
 enum {
 	PDO_FB_ATTR_DATE_FORMAT = PDO_ATTR_DRIVER_SPECIFIC,
 	PDO_FB_ATTR_TIME_FORMAT,
diff --git a/ext/pdo_firebird/tests/autocommit.phpt b/ext/pdo_firebird/tests/autocommit.phpt
new file mode 100644
index 0000000000000..5ba61e11f7a8d
--- /dev/null
+++ b/ext/pdo_firebird/tests/autocommit.phpt
@@ -0,0 +1,80 @@
+--TEST--
+PDO_Firebird: auto commit
+--EXTENSIONS--
+pdo_firebird
+--SKIPIF--
+<?php require('skipif.inc'); ?>
+--XLEAK--
+A bug in firebird causes a memory leak when calling `isc_attach_database()`.
+See https://github.com/FirebirdSQL/firebird/issues/7849
+--FILE--
+<?php
+/* Part of the error messages probably vary depending on the version of Firebird,
+ * so it won't check them in detail. */
+
+require("testdb.inc");
+$table = "autocommit_pdo_firebird";
+
+echo "========== in auto commit mode ==========\n";
+echo "auto commit mode ON\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+
+echo "create table and insert\n";
+$dbh->exec("CREATE TABLE {$table} (val INT)");
+$dbh->exec("INSERT INTO {$table} VALUES (35)");
+
+echo "new connection\n";
+unset($dbh);
+$dbh = new PDO(PDO_FIREBIRD_TEST_DSN, PDO_FIREBIRD_TEST_USER, PDO_FIREBIRD_TEST_PASS);
+
+$r = $dbh->query("SELECT * FROM {$table}");
+var_dump($r->fetchAll());
+
+echo "========== not in auto commit mode ==========\n";
+echo "auto commit mode OFF\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+
+echo "insert, expect error\n";
+try {
+    $dbh->exec("INSERT INTO {$table} VALUES (35)");
+} catch (PDOException $e) {
+    echo $e->getMessage()."\n\n";
+}
+
+echo "select, expect error\n";
+try {
+    $r = $dbh->query("SELECT * FROM {$table}");
+} catch (PDOException $e) {
+    echo $e->getMessage()."\n\n";
+}
+
+echo "done!";
+?>
+--CLEAN--
+<?php
+require 'testdb.inc';
+@$dbh->exec("DROP TABLE autocommit_pdo_firebird");
+?>
+--EXPECTF--
+========== in auto commit mode ==========
+auto commit mode ON
+create table and insert
+new connection
+array(1) {
+  [0]=>
+  array(2) {
+    ["VAL"]=>
+    int(35)
+    [0]=>
+    int(35)
+  }
+}
+========== not in auto commit mode ==========
+auto commit mode OFF
+insert, expect error
+SQLSTATE[08003]: Connection does not exist: %s
+
+select, expect error
+SQLSTATE[08003]: Connection does not exist: %s
+
+done!
diff --git a/ext/pdo_firebird/tests/autocommit_change_mode.phpt b/ext/pdo_firebird/tests/autocommit_change_mode.phpt
new file mode 100644
index 0000000000000..4eacdaa697535
--- /dev/null
+++ b/ext/pdo_firebird/tests/autocommit_change_mode.phpt
@@ -0,0 +1,134 @@
+--TEST--
+PDO_Firebird: change auto commit
+--EXTENSIONS--
+pdo_firebird
+--SKIPIF--
+<?php require('skipif.inc'); ?>
+--XLEAK--
+A bug in firebird causes a memory leak when calling `isc_attach_database()`.
+See https://github.com/FirebirdSQL/firebird/issues/7849
+--FILE--
+<?php
+require("testdb.inc");
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+
+echo "========== not in manually transaction ==========\n";
+
+echo "auto commit ON from ON\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+echo "Success\n\n";
+
+echo "auto commit OFF from ON\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+echo "Success\n\n";
+
+echo "auto commit OFF from OFF\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+echo "Success\n\n";
+
+echo "auto commit ON from OFF\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+echo "Success\n\n";
+
+echo "========== in manually transaction ==========\n";
+
+echo "begin transaction\n";
+$dbh->beginTransaction();
+echo "\n";
+
+echo "auto commit ON from ON, expect error\n";
+try {
+    $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+} catch (PDOException $e) {
+    var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+    echo $e->getMessage()."\n\n";
+}
+
+echo "auto commit OFF from ON, expect error\n";
+try {
+    $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+} catch (PDOException $e) {
+    var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+    echo $e->getMessage()."\n\n";
+}
+
+echo "end transaction\n";
+$dbh->rollback();
+
+echo "auto commit OFF\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+
+echo "begin transaction\n";
+$dbh->beginTransaction();
+echo "\n";
+
+echo "auto commit ON from OFF, expect error\n";
+try {
+    $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+} catch (PDOException $e) {
+    var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+    echo $e->getMessage()."\n\n";
+}
+
+echo "auto commit OFF from OFF, expect error\n";
+try {
+    $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+} catch (PDOException $e) {
+    var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+    echo $e->getMessage()."\n\n";
+}
+
+echo "end transaction\n";
+$dbh->rollback();
+echo "\n";
+
+echo "done!";
+?>
+--EXPECT--
+========== not in manually transaction ==========
+auto commit ON from ON
+int(1)
+Success
+
+auto commit OFF from ON
+int(0)
+Success
+
+auto commit OFF from OFF
+int(0)
+Success
+
+auto commit ON from OFF
+int(1)
+Success
+
+========== in manually transaction ==========
+begin transaction
+
+auto commit ON from ON, expect error
+int(1)
+SQLSTATE[HY000]: General error: Cannot change autocommit mode while a transaction is already open
+
+auto commit OFF from ON, expect error
+int(1)
+SQLSTATE[HY000]: General error: Cannot change autocommit mode while a transaction is already open
+
+end transaction
+auto commit OFF
+begin transaction
+
+auto commit ON from OFF, expect error
+int(0)
+SQLSTATE[HY000]: General error: Cannot change autocommit mode while a transaction is already open
+
+auto commit OFF from OFF, expect error
+int(0)
+SQLSTATE[HY000]: General error: Cannot change autocommit mode while a transaction is already open
+
+end transaction
+
+done!
diff --git a/ext/pdo_firebird/tests/bug_47415.phpt b/ext/pdo_firebird/tests/bug_47415.phpt
index e67a1b3f6da3a..6a7fc6ff7f77d 100644
--- a/ext/pdo_firebird/tests/bug_47415.phpt
+++ b/ext/pdo_firebird/tests/bug_47415.phpt
@@ -16,8 +16,6 @@ $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
 $dbh->exec('CREATE TABLE test47415 (idx int NOT NULL PRIMARY KEY, txt VARCHAR(20))');
 $dbh->exec('INSERT INTO test47415 VALUES(0, \'String0\')');
 
-$dbh->commit();
-
 $query = "SELECT idx, txt FROM test47415 ORDER by idx";
 $idx = $txt = 0;
 $stmt = $dbh->prepare($query);
@@ -32,8 +30,6 @@ var_dump($stmt->rowCount());
 $stmt = $dbh->prepare('DELETE FROM test47415');
 $stmt->execute();
 
-$dbh->commit();
-
 unset($stmt);
 unset($dbh);
 ?>
diff --git a/ext/pdo_firebird/tests/bug_48877.phpt b/ext/pdo_firebird/tests/bug_48877.phpt
index ecdd40baa8de0..f7fa25ba1c834 100644
--- a/ext/pdo_firebird/tests/bug_48877.phpt
+++ b/ext/pdo_firebird/tests/bug_48877.phpt
@@ -18,7 +18,6 @@ $dbh->exec('CREATE TABLE test48877 (A integer)');
 $dbh->exec("INSERT INTO test48877 VALUES ('1')");
 $dbh->exec("INSERT INTO test48877 VALUES ('2')");
 $dbh->exec("INSERT INTO test48877 VALUES ('3')");
-$dbh->commit();
 
 $query = "SELECT * FROM test48877 WHERE A = :paramno";
 
@@ -33,7 +32,6 @@ var_dump($stmt->rowCount());
 $stmt = $dbh->prepare('DELETE FROM test48877');
 $stmt->execute();
 
-$dbh->commit();
 unset($stmt);
 unset($dbh);
 
diff --git a/ext/pdo_firebird/tests/bug_53280.phpt b/ext/pdo_firebird/tests/bug_53280.phpt
index 4b22ec4fa162e..b1da6789ba84d 100644
--- a/ext/pdo_firebird/tests/bug_53280.phpt
+++ b/ext/pdo_firebird/tests/bug_53280.phpt
@@ -14,7 +14,6 @@ require("testdb.inc");
 
 $dbh->exec('CREATE TABLE test53280(A VARCHAR(30), B VARCHAR(30), C VARCHAR(30))');
 $dbh->exec("INSERT INTO test53280 VALUES ('A', 'B', 'C')");
-$dbh->commit();
 
 $stmt1 = "SELECT B FROM test53280 WHERE A = ? AND B = ?";
 $stmt2 = "SELECT B, C FROM test53280 WHERE A = ? AND B = ?";
@@ -29,7 +28,6 @@ $stmth1->execute(array('A', 'B'));
 $rows = $stmth1->fetchAll(); // <------- segfault
 var_dump($rows);
 
-$dbh->commit();
 unset($stmth1);
 unset($stmth2);
 unset($stmt);
diff --git a/ext/pdo_firebird/tests/bug_62024.phpt b/ext/pdo_firebird/tests/bug_62024.phpt
index 9817e550ffc44..2f8fa09a93635 100644
--- a/ext/pdo_firebird/tests/bug_62024.phpt
+++ b/ext/pdo_firebird/tests/bug_62024.phpt
@@ -15,8 +15,6 @@ require("testdb.inc");
 $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
 $dbh->exec("CREATE TABLE test62024 (ID INTEGER NOT NULL, TEXT VARCHAR(10))");
 
-$dbh->commit();
-
 //start actual test
 
 $sql = "insert into test62024 (id, text) values (?, ?)";
@@ -31,15 +29,11 @@ var_dump($res);
 $res = $sttmt->execute($args_err);
 var_dump($res);
 
-$dbh->commit();
-
 
 //teardown test data
 $sttmt = $dbh->prepare('DELETE FROM test62024');
 $sttmt->execute();
 
-$dbh->commit();
-
 unset($sttmt);
 unset($dbh);
 
diff --git a/ext/pdo_firebird/tests/bug_64037.phpt b/ext/pdo_firebird/tests/bug_64037.phpt
index c37268352cd28..545e6feaf6948 100644
--- a/ext/pdo_firebird/tests/bug_64037.phpt
+++ b/ext/pdo_firebird/tests/bug_64037.phpt
@@ -18,8 +18,6 @@ $dbh->exec("INSERT INTO test64037 (ID, TEXT, COST) VALUES (1, 'test', -1.0)");
 $dbh->exec("INSERT INTO test64037 (ID, TEXT, COST) VALUES (2, 'test', -0.99)");
 $dbh->exec("INSERT INTO test64037 (ID, TEXT, COST) VALUES (3, 'test', -1.01)");
 
-$dbh->commit();
-
 $query = "SELECT * from test64037 order by ID";
 $stmt = $dbh->prepare($query);
 $stmt->execute();
@@ -32,8 +30,6 @@ var_dump($rows[2]['COST']);
 $stmt = $dbh->prepare('DELETE FROM test64037');
 $stmt->execute();
 
-$dbh->commit();
-
 unset($stmt);
 unset($dbh);
 
diff --git a/ext/pdo_firebird/tests/ddl2.phpt b/ext/pdo_firebird/tests/ddl2.phpt
new file mode 100644
index 0000000000000..f258fb6f930c1
--- /dev/null
+++ b/ext/pdo_firebird/tests/ddl2.phpt
@@ -0,0 +1,37 @@
+--TEST--
+PDO_Firebird: DDL/transactions 2
+--EXTENSIONS--
+pdo_firebird
+--SKIPIF--
+<?php require('skipif.inc'); ?>
+--XLEAK--
+A bug in firebird causes a memory leak when calling `isc_attach_database()`.
+See https://github.com/FirebirdSQL/firebird/issues/7849
+--FILE--
+<?php
+require("testdb.inc");
+
+$dbh->exec("CREATE TABLE test_ddl2 (val int)");
+
+$dbh->beginTransaction();
+$dbh->exec("INSERT INTO test_ddl2 (val) VALUES (120)");
+$dbh->exec("CREATE TABLE test_ddl2_2 (val INT)");
+$dbh->rollback();
+
+$result = $dbh->query("SELECT * FROM test_ddl2");
+var_dump($result->fetchAll());
+
+unset($dbh);
+echo "done\n";
+?>
+--CLEAN--
+<?php
+require("testdb.inc");
+$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
+@$dbh->exec('DROP TABLE test_ddl2');
+@$dbh->exec('DROP TABLE test_ddl2_2');
+?>
+--EXPECT--
+array(0) {
+}
+done
diff --git a/ext/pdo_firebird/tests/payload_test.phpt b/ext/pdo_firebird/tests/payload_test.phpt
index 027c101d80b52..e119a4068f622 100644
--- a/ext/pdo_firebird/tests/payload_test.phpt
+++ b/ext/pdo_firebird/tests/payload_test.phpt
@@ -17,6 +17,9 @@ $dsn = "firebird:dbname=inet://$address/test";
 $username = 'SYSDBA';
 $password = 'masterkey';
 
-new PDO($dsn, $username, $password, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
+new PDO($dsn, $username, $password, [
+    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+    PDO::ATTR_AUTOCOMMIT => false,
+]);
 ?>
 --EXPECT--
diff --git a/ext/pdo_firebird/tests/rowCount.phpt b/ext/pdo_firebird/tests/rowCount.phpt
index ec6748dd143e6..d435cc10a249c 100644
--- a/ext/pdo_firebird/tests/rowCount.phpt
+++ b/ext/pdo_firebird/tests/rowCount.phpt
@@ -16,7 +16,6 @@ $dbh->exec('CREATE TABLE test_rowcount (A VARCHAR(10))');
 $dbh->exec("INSERT INTO test_rowcount VALUES ('A')");
 $dbh->exec("INSERT INTO test_rowcount VALUES ('A')");
 $dbh->exec("INSERT INTO test_rowcount VALUES ('B')");
-$dbh->commit();
 
 $query = "SELECT * FROM test_rowcount WHERE A = ?";
 
@@ -30,14 +29,11 @@ var_dump($stmt->rowCount());
 $stmt = $dbh->prepare('UPDATE test_rowcount SET A="A" WHERE A != ?');
 $stmt->execute(array('A'));
 var_dump($stmt->rowCount());
-$dbh->commit();
 
 $stmt = $dbh->prepare('DELETE FROM test_rowcount');
 $stmt->execute();
 var_dump($stmt->rowCount());
 
-$dbh->commit();
-
 unset($stmt);
 unset($dbh);