diff --git a/ext/date/php_date.c b/ext/date/php_date.c
index b5fa67d22c122..ba692027c3577 100644
--- a/ext/date/php_date.c
+++ b/ext/date/php_date.c
@@ -320,6 +320,7 @@ static void date_throw_uninitialized_error(zend_class_entry *ce)
 		}
 		if (ce_ptr->type != ZEND_INTERNAL_CLASS) {
 			zend_throw_error(date_ce_date_object_error, "Object of type %s not been correctly initialized by calling parent::__construct() in its constructor", ZSTR_VAL(ce->name));
+			return;
 		}
 		zend_throw_error(date_ce_date_object_error, "Object of type %s (inheriting %s) has not been correctly initialized by calling parent::__construct() in its constructor", ZSTR_VAL(ce->name), ZSTR_VAL(ce_ptr->name));
 	}
@@ -3866,6 +3867,7 @@ PHP_METHOD(DateTimeZone, __construct)
 	if (!timezone_initialize(tzobj, ZSTR_VAL(tz), ZSTR_LEN(tz), &exception_message)) {
 		zend_throw_exception_ex(date_ce_date_invalid_timezone_exception, 0, "DateTimeZone::__construct(): %s", exception_message);
 		efree(exception_message);
+		RETURN_THROWS();
 	}
 }
 /* }}} */
@@ -4423,11 +4425,6 @@ PHP_METHOD(DateInterval, __construct)
 
 static void php_date_interval_initialize_from_hash(zval **return_value, php_interval_obj **intobj, HashTable *myht) /* {{{ */
 {
-	/* If ->diff is already set, then we need to free it first */
-	if ((*intobj)->diff) {
-		timelib_rel_time_dtor((*intobj)->diff);
-	}
-
 	/* If we have a date_string, use that instead */
 	zval *date_str = zend_hash_str_find(myht, "date_string", strlen("date_string"));
 	if (date_str && Z_TYPE_P(date_str) == IS_STRING) {
@@ -4442,6 +4439,14 @@ static void php_date_interval_initialize_from_hash(zval **return_value, php_inte
 				Z_STRVAL_P(date_str),
 				err->error_messages[0].position,
 				err->error_messages[0].character ? err->error_messages[0].character : ' ', err->error_messages[0].message);
+				timelib_time_dtor(time);
+				timelib_error_container_dtor(err);
+				return;
+		}
+
+		/* If ->diff is already set, then we need to free it first */
+		if ((*intobj)->diff) {
+			timelib_rel_time_dtor((*intobj)->diff);
 		}
 
 		(*intobj)->diff = timelib_rel_time_clone(&time->relative);
@@ -4456,6 +4461,11 @@ static void php_date_interval_initialize_from_hash(zval **return_value, php_inte
 		return;
 	}
 
+	/* If ->diff is already set, then we need to free it first */
+	if ((*intobj)->diff) {
+		timelib_rel_time_dtor((*intobj)->diff);
+	}
+
 	/* Set new value */
 	(*intobj)->diff = timelib_rel_time_ctor();
 
diff --git a/ext/date/tests/date_interval_set_state_error1.phpt b/ext/date/tests/date_interval_set_state_error1.phpt
new file mode 100644
index 0000000000000..ee68de8db4666
--- /dev/null
+++ b/ext/date/tests/date_interval_set_state_error1.phpt
@@ -0,0 +1,68 @@
+--TEST--
+Test that DateInterval::__unserialize() doesn't modify state in case of a date_string format error
+--FILE--
+<?php
+
+$interval = new DateInterval("P1Y1DT1H1M");
+
+var_dump($interval);
+
+try {
+    $interval->__unserialize(
+        [
+            "date_string" => "wrong",
+        ]
+    );
+} catch (Error $e) {
+    echo $e->getMessage() . "\n";
+}
+
+var_dump($interval);
+
+?>
+--EXPECTF--
+object(DateInterval)#%d (%d) {
+  ["y"]=>
+  int(1)
+  ["m"]=>
+  int(0)
+  ["d"]=>
+  int(1)
+  ["h"]=>
+  int(1)
+  ["i"]=>
+  int(1)
+  ["s"]=>
+  int(0)
+  ["f"]=>
+  float(0)
+  ["invert"]=>
+  int(0)
+  ["days"]=>
+  bool(false)
+  ["from_string"]=>
+  bool(false)
+}
+Unknown or bad format (wrong) at position 0 (w) while unserializing: The timezone could not be found in the database
+object(DateInterval)#%d (%d) {
+  ["y"]=>
+  int(1)
+  ["m"]=>
+  int(0)
+  ["d"]=>
+  int(1)
+  ["h"]=>
+  int(1)
+  ["i"]=>
+  int(1)
+  ["s"]=>
+  int(0)
+  ["f"]=>
+  float(0)
+  ["invert"]=>
+  int(0)
+  ["days"]=>
+  bool(false)
+  ["from_string"]=>
+  bool(false)
+}