diff --git a/Zend/zend_API.c b/Zend/zend_API.c
index e58e331773d..7d16e376c3d 100644
--- a/Zend/zend_API.c
+++ b/Zend/zend_API.c
@@ -2581,6 +2581,7 @@ ZEND_API zend_class_entry *zend_register_internal_interface(zend_class_entry *or
 ZEND_API int zend_register_class_alias_ex(const char *name, size_t name_len, zend_class_entry *ce, int persistent) /* {{{ */
 {
 	zend_string *lcname;
+	zval zv, *ret;
 
 	/* TODO: Move this out of here in 7.4. */
 	if (persistent && EG(current_module) && EG(current_module)->type == MODULE_TEMPORARY) {
@@ -2598,9 +2599,11 @@ ZEND_API int zend_register_class_alias_ex(const char *name, size_t name_len, zen
 	zend_assert_valid_class_name(lcname);
 
 	lcname = zend_new_interned_string(lcname);
-	ce = zend_hash_add_ptr(CG(class_table), lcname, ce);
+
+	ZVAL_ALIAS_PTR(&zv, ce);
+	ret = zend_hash_add(CG(class_table), lcname, &zv);
 	zend_string_release_ex(lcname, 0);
-	if (ce) {
+	if (ret) {
 		if (!(ce->ce_flags & ZEND_ACC_IMMUTABLE)) {
 			ce->refcount++;
 		}
diff --git a/Zend/zend_types.h b/Zend/zend_types.h
index 3ff94eb574c..e32538591b6 100644
--- a/Zend/zend_types.h
+++ b/Zend/zend_types.h
@@ -541,6 +541,7 @@ struct _zend_ast_ref {
 /* internal types */
 #define IS_INDIRECT             	15
 #define IS_PTR						16
+#define IS_ALIAS_PTR				17
 #define _IS_ERROR					17
 
 /* used for casts */
@@ -1075,6 +1076,11 @@ static zend_always_inline uint32_t zval_gc_info(uint32_t gc_type_info) {
 		Z_TYPE_INFO_P(z) = IS_PTR;								\
 	} while (0)
 
+#define ZVAL_ALIAS_PTR(z, p) do {								\
+		Z_PTR_P(z) = (p);										\
+		Z_TYPE_INFO_P(z) = IS_ALIAS_PTR;						\
+	} while (0)
+
 #define ZVAL_ERROR(z) do {				\
 		Z_TYPE_INFO_P(z) = _IS_ERROR;	\
 	} while (0)
diff --git a/ext/opcache/ZendAccelerator.c b/ext/opcache/ZendAccelerator.c
index e46f3c48c75..5f19a90cdee 100644
--- a/ext/opcache/ZendAccelerator.c
+++ b/ext/opcache/ZendAccelerator.c
@@ -3323,7 +3323,7 @@ static void preload_move_user_classes(HashTable *src, HashTable *dst)
 				}
 			}
 			if (copy) {
-				_zend_hash_append_ptr(dst, p->key, ce);
+				_zend_hash_append(dst, p->key, &p->val);
 			} else {
 				orig_dtor(&p->val);
 			}
@@ -4332,7 +4332,7 @@ static void preload_load(void)
 		Bucket *end = p + ZCSG(preload_script)->script.class_table.nNumUsed;
 
 		for (; p != end; p++) {
-			_zend_hash_append_ptr_ex(CG(class_table), p->key, Z_PTR(p->val), 1);
+			_zend_hash_append_ex(CG(class_table), p->key, &p->val, 1);
 		}
 	}
 
diff --git a/ext/opcache/tests/preload_class_alias_2.inc b/ext/opcache/tests/preload_class_alias_2.inc
new file mode 100644
index 00000000000..3d0a70d8822
--- /dev/null
+++ b/ext/opcache/tests/preload_class_alias_2.inc
@@ -0,0 +1,4 @@
+<?php
+interface I {}
+class B implements I {}
+class_alias('B', 'C');
diff --git a/ext/opcache/tests/preload_class_alias_2.phpt b/ext/opcache/tests/preload_class_alias_2.phpt
new file mode 100644
index 00000000000..6dc2c21a8a2
--- /dev/null
+++ b/ext/opcache/tests/preload_class_alias_2.phpt
@@ -0,0 +1,17 @@
+--TEST--
+Bug #78918.2: Class alias during preloading causes assertion failure
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.optimization_level=-1
+opcache.preload={PWD}/preload_class_alias_2.inc
+--SKIPIF--
+<?php require_once('skipif.inc'); ?>
+--FILE--
+<?php
+var_dump(class_exists('B'));
+var_dump(class_exists('C'));
+?>
+--EXPECT--
+bool(true)
+bool(true)
diff --git a/ext/opcache/zend_persist.c b/ext/opcache/zend_persist.c
index a6bc78a6447..e78e3cbfce4 100644
--- a/ext/opcache/zend_persist.c
+++ b/ext/opcache/zend_persist.c
@@ -1080,8 +1080,11 @@ static void zend_accel_persist_class_table(HashTable *class_table)
 		zend_accel_store_interned_string(p->key);
 		zend_persist_class_entry(&p->val);
 	} ZEND_HASH_FOREACH_END();
-    ZEND_HASH_FOREACH_PTR(class_table, ce) {
-		zend_update_parent_ce(ce);
+    ZEND_HASH_FOREACH_BUCKET(class_table, p) {
+		if (EXPECTED(Z_TYPE(p->val) != IS_ALIAS_PTR)) {
+			ce = Z_PTR(p->val);
+			zend_update_parent_ce(ce);
+		}
 	} ZEND_HASH_FOREACH_END();
 }