diff --git a/UPGRADING.INTERNALS b/UPGRADING.INTERNALS
index 4ec4091982462..9f9fa62f8fe51 100644
--- a/UPGRADING.INTERNALS
+++ b/UPGRADING.INTERNALS
@@ -79,6 +79,10 @@ PHP 8.3 INTERNALS UPGRADE NOTES
    - The function pcre_get_compiled_regex_ex has been removed.
    Use pcre_get_compiled_regex instead.
 
+ e. ext/spl
+   - The PHPAPI spl_iterator_apply() function now returns zend_result instead of int.
+     There are no functional changes.
+
 ========================
 4. OpCode changes
 ========================
diff --git a/ext/spl/spl_heap.c b/ext/spl/spl_heap.c
index 64fe962ee2de3..80c186acc0dd2 100644
--- a/ext/spl/spl_heap.c
+++ b/ext/spl/spl_heap.c
@@ -121,7 +121,7 @@ static void spl_ptr_heap_pqueue_elem_ctor(void *elem) { /* {{{ */
 }
 /* }}} */
 
-static int spl_ptr_heap_cmp_cb_helper(zval *object, spl_heap_object *heap_object, zval *a, zval *b, zend_long *result) { /* {{{ */
+static zend_result spl_ptr_heap_cmp_cb_helper(zval *object, spl_heap_object *heap_object, zval *a, zval *b, zend_long *result) { /* {{{ */
 	zval zresult;
 
 	zend_call_method_with_2_params(Z_OBJ_P(object), heap_object->std.ce, &heap_object->fptr_cmp, "compare", &zresult, a, b);
@@ -302,7 +302,7 @@ static void *spl_ptr_heap_top(spl_ptr_heap *heap) { /* {{{ */
 }
 /* }}} */
 
-static int spl_ptr_heap_delete_top(spl_ptr_heap *heap, void *elem, void *cmp_userdata) { /* {{{ */
+static zend_result spl_ptr_heap_delete_top(spl_ptr_heap *heap, void *elem, void *cmp_userdata) { /* {{{ */
 	int i, j;
 	const int limit = (heap->count-1)/2;
 	void *bottom;
diff --git a/ext/spl/spl_iterators.c b/ext/spl/spl_iterators.c
index 39791039b1d83..e92247a4b6082 100644
--- a/ext/spl/spl_iterators.c
+++ b/ext/spl/spl_iterators.c
@@ -514,7 +514,7 @@ static zend_object_iterator *spl_recursive_it_get_iterator(zend_class_entry *ce,
 	return (zend_object_iterator*)iterator;
 }
 
-static int spl_get_iterator_from_aggregate(zval *retval, zend_class_entry *ce, zend_object *obj) {
+static zend_result spl_get_iterator_from_aggregate(zval *retval, zend_class_entry *ce, zend_object *obj) {
 	zend_function **getiterator_cache =
 		ce->iterator_funcs_ptr ? &ce->iterator_funcs_ptr->zf_new_iterator : NULL;
 	zend_call_method_with_0_params(obj, ce, getiterator_cache, "getiterator", retval);
@@ -1301,9 +1301,9 @@ static zend_function *spl_dual_it_get_method(zend_object **object, zend_string *
 
 #define APPENDIT_CHECK_CTOR(intern) SPL_CHECK_CTOR(intern, AppendIterator)
 
-static inline int spl_dual_it_fetch(spl_dual_it_object *intern, int check_more);
+static inline zend_result spl_dual_it_fetch(spl_dual_it_object *intern, int check_more);
 
-static inline int spl_cit_check_flags(zend_long flags)
+static inline zend_result spl_cit_check_flags(zend_long flags)
 {
 	zend_long cnt = 0;
 
@@ -1542,7 +1542,7 @@ static inline int spl_dual_it_valid(spl_dual_it_object *intern)
 	return intern->inner.iterator->funcs->valid(intern->inner.iterator);
 }
 
-static inline int spl_dual_it_fetch(spl_dual_it_object *intern, int check_more)
+static inline zend_result spl_dual_it_fetch(spl_dual_it_object *intern, int check_more)
 {
 	zval *data;
 
@@ -2874,7 +2874,7 @@ PHP_METHOD(EmptyIterator, next)
 	}
 } /* }}} */
 
-int spl_append_it_next_iterator(spl_dual_it_object *intern) /* {{{*/
+zend_result spl_append_it_next_iterator(spl_dual_it_object *intern) /* {{{*/
 {
 	spl_dual_it_free(intern);
 
@@ -3051,7 +3051,7 @@ PHP_METHOD(AppendIterator, getArrayIterator)
 	RETURN_COPY_DEREF(value);
 } /* }}} */
 
-PHPAPI int spl_iterator_apply(zval *obj, spl_iterator_apply_func_t apply_func, void *puser)
+PHPAPI zend_result spl_iterator_apply(zval *obj, spl_iterator_apply_func_t apply_func, void *puser)
 {
 	zend_object_iterator   *iter;
 	zend_class_entry       *ce = Z_OBJCE_P(obj);
diff --git a/ext/spl/spl_iterators.h b/ext/spl/spl_iterators.h
index d8d50862a26fc..3c78bb97bf8c0 100644
--- a/ext/spl/spl_iterators.h
+++ b/ext/spl/spl_iterators.h
@@ -114,6 +114,6 @@ typedef enum {
 
 typedef int (*spl_iterator_apply_func_t)(zend_object_iterator *iter, void *puser);
 
-PHPAPI int spl_iterator_apply(zval *obj, spl_iterator_apply_func_t apply_func, void *puser);
+PHPAPI zend_result spl_iterator_apply(zval *obj, spl_iterator_apply_func_t apply_func, void *puser);
 
 #endif /* SPL_ITERATORS_H */