diff --git a/.gitattributes b/.gitattributes
index d71a50b7b13..f8b91505bc9 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -23,3 +23,6 @@
 **/*_arginfo.h linguist-generated
 /Zend/zend_vm_execute.h linguist-generated
 /Zend/zend_vm_opcodes.{h,c} linguist-generated
+
+# The OSS fuzz files are bunary
+/ext/date/tests/ossfuzz*.txt binary
diff --git a/ext/date/php_date.c b/ext/date/php_date.c
index 10992e3f487..9bfc4e19740 100644
--- a/ext/date/php_date.c
+++ b/ext/date/php_date.c
@@ -2706,6 +2706,7 @@ PHP_METHOD(DateTime, __set_state)
 	dateobj = Z_PHPDATE_P(return_value);
 	if (!php_date_initialize_from_hash(&dateobj, myht)) {
 		zend_throw_error(NULL, "Invalid serialization data for DateTime object");
+		RETURN_THROWS();
 	}
 }
 /* }}} */
@@ -2727,6 +2728,7 @@ PHP_METHOD(DateTimeImmutable, __set_state)
 	dateobj = Z_PHPDATE_P(return_value);
 	if (!php_date_initialize_from_hash(&dateobj, myht)) {
 		zend_throw_error(NULL, "Invalid serialization data for DateTimeImmutable object");
+		RETURN_THROWS();
 	}
 }
 /* }}} */
@@ -2789,7 +2791,7 @@ static void restore_custom_datetime_properties(zval *object, HashTable *myht)
 	zval             *prop_val;
 
 	ZEND_HASH_MAP_FOREACH_STR_KEY_VAL(myht, prop_name, prop_val) {
-		if (date_time_is_internal_property(prop_name)) {
+		if (!prop_name || (Z_TYPE_P(prop_val) == IS_REFERENCE) || date_time_is_internal_property(prop_name)) {
 			continue;
 		}
 		add_property_zval_ex(object, ZSTR_VAL(prop_name), ZSTR_LEN(prop_name), prop_val);
@@ -2813,6 +2815,7 @@ PHP_METHOD(DateTime, __unserialize)
 
 	if (!php_date_initialize_from_hash(&dateobj, myht)) {
 		zend_throw_error(NULL, "Invalid serialization data for DateTime object");
+		RETURN_THROWS();
 	}
 
 	restore_custom_datetime_properties(object, myht);
@@ -2836,6 +2839,7 @@ PHP_METHOD(DateTimeImmutable, __unserialize)
 
 	if (!php_date_initialize_from_hash(&dateobj, myht)) {
 		zend_throw_error(NULL, "Invalid serialization data for DateTimeImmutable object");
+		RETURN_THROWS();
 	}
 
 	restore_custom_datetime_properties(object, myht);
@@ -3821,7 +3825,7 @@ static void restore_custom_datetimezone_properties(zval *object, HashTable *myht
 	zval             *prop_val;
 
 	ZEND_HASH_MAP_FOREACH_STR_KEY_VAL(myht, prop_name, prop_val) {
-		if (date_timezone_is_internal_property(prop_name)) {
+		if (!prop_name || (Z_TYPE_P(prop_val) == IS_REFERENCE) || date_timezone_is_internal_property(prop_name)) {
 			continue;
 		}
 		add_property_zval_ex(object, ZSTR_VAL(prop_name), ZSTR_LEN(prop_name), prop_val);
@@ -4449,7 +4453,7 @@ static void restore_custom_dateinterval_properties(zval *object, HashTable *myht
 	zval             *prop_val;
 
 	ZEND_HASH_MAP_FOREACH_STR_KEY_VAL(myht, prop_name, prop_val) {
-		if (date_interval_is_internal_property(prop_name)) {
+		if (!prop_name || (Z_TYPE_P(prop_val) == IS_REFERENCE) || date_interval_is_internal_property(prop_name)) {
 			continue;
 		}
 		add_property_zval_ex(object, ZSTR_VAL(prop_name), ZSTR_LEN(prop_name), prop_val);
@@ -5411,7 +5415,7 @@ static void restore_custom_dateperiod_properties(zval *object, HashTable *myht)
 	zval             *prop_val;
 
 	ZEND_HASH_MAP_FOREACH_STR_KEY_VAL(myht, prop_name, prop_val) {
-		if (date_period_is_internal_property(prop_name)) {
+		if (!prop_name || (Z_TYPE_P(prop_val) == IS_REFERENCE) || date_period_is_internal_property(prop_name)) {
 			continue;
 		}
 		add_property_zval_ex(object, ZSTR_VAL(prop_name), ZSTR_LEN(prop_name), prop_val);
diff --git a/ext/date/tests/ossfuzz-55589.txt b/ext/date/tests/ossfuzz-55589.txt
new file mode 100644
index 00000000000..77b4041ffa2
--- /dev/null
+++ b/ext/date/tests/ossfuzz-55589.txt
@@ -0,0 +1 @@
+|O:12:"DaTeInterval":2:{i:2;r:1;i:0;R:2;
\ No newline at end of file
diff --git a/ext/date/tests/ossfuzz-55599.txt b/ext/date/tests/ossfuzz-55599.txt
new file mode 100644
index 00000000000..624a0058c8f
--- /dev/null
+++ b/ext/date/tests/ossfuzz-55599.txt
@@ -0,0 +1 @@
+|O:8:"DateTime":1:{i:1;d:2;
\ No newline at end of file
diff --git a/ext/date/tests/ossfuzz-55727.txt b/ext/date/tests/ossfuzz-55727.txt
new file mode 100644
index 00000000000..02389f0815c
Binary files /dev/null and b/ext/date/tests/ossfuzz-55727.txt differ
diff --git a/ext/date/tests/unserialize-test.phpt b/ext/date/tests/unserialize-test.phpt
new file mode 100644
index 00000000000..b88ef0a1fcf
--- /dev/null
+++ b/ext/date/tests/unserialize-test.phpt
@@ -0,0 +1,39 @@
+--TEST--
+Test DateInterval::__unserialize OSS fuzz issues
+--FILE--
+<?php
+$files = [
+	'ossfuzz-55589.txt',
+	'ossfuzz-55599.txt',
+	'ossfuzz-55727.txt',
+];
+
+foreach ($files as $file) {
+	echo "{$file}: ";
+
+	$s = file_get_contents(__DIR__ . "/{$file}");
+
+	try {
+		$x = unserialize(substr($s, strpos($s, "|") + 1));
+	} catch (Error $e) {
+		echo get_class($e), ': ', $e->getMessage(), "\n";
+	}
+	var_dump($x);
+	echo "\n\n";
+}
+?>
+--EXPECTF--
+ossfuzz-55589.txt: 
+%s: unserialize(): Error at offset 39 of 39 bytes in %sunserialize-test.php on line 14
+bool(false)
+
+
+ossfuzz-55599.txt: 
+%s: unserialize(): Error at offset 26 of 26 bytes in %sunserialize-test.php on line 14
+Error: Invalid serialization data for DateTime object
+bool(false)
+
+
+ossfuzz-55727.txt: 
+%s: unserialize(): Error at offset 230 of 509 bytes in %sunserialize-test.php on line 14
+bool(false)