diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index eb74893886ab4..cb8df3f7d3b5a 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -379,7 +379,7 @@ void zend_init_compiler_data_structures(void) /* {{{ */
 
 	CG(encoding_declared) = 0;
 	CG(memoized_exprs) = NULL;
-	CG(memoize_mode) = 0;
+	CG(memoize_mode) = ZEND_MEMOIZE_NONE;
 }
 /* }}} */
 
@@ -2426,13 +2426,9 @@ static void zend_emit_jmp_null(znode *obj_node, uint32_t bp_type)
 	zend_stack_push(&CG(short_circuiting_opnums), &jmp_null_opnum);
 }
 
-#define ZEND_MEMOIZE_NONE 0
-#define ZEND_MEMOIZE_COMPILE 1
-#define ZEND_MEMOIZE_FETCH 2
-
 static void zend_compile_memoized_expr(znode *result, zend_ast *expr) /* {{{ */
 {
-	int memoize_mode = CG(memoize_mode);
+	const zend_memoize_mode memoize_mode = CG(memoize_mode);
 	if (memoize_mode == ZEND_MEMOIZE_COMPILE) {
 		znode memoized_result;
 
@@ -9184,7 +9180,7 @@ static void zend_compile_assign_coalesce(znode *result, zend_ast *ast) /* {{{ */
 	/* Remember expressions compiled during the initial BP_VAR_IS lookup,
 	 * to avoid double-evaluation when we compile again with BP_VAR_W. */
 	HashTable *orig_memoized_exprs = CG(memoized_exprs);
-	int orig_memoize_mode = CG(memoize_mode);
+	const zend_memoize_mode orig_memoize_mode = CG(memoize_mode);
 
 	zend_ensure_writable_variable(var_ast);
 	if (is_this_fetch(var_ast)) {
diff --git a/Zend/zend_globals.h b/Zend/zend_globals.h
index a2439b80eabcb..0e86187021746 100644
--- a/Zend/zend_globals.h
+++ b/Zend/zend_globals.h
@@ -70,6 +70,12 @@ typedef struct _zend_ini_entry zend_ini_entry;
 typedef struct _zend_fiber_context zend_fiber_context;
 typedef struct _zend_fiber zend_fiber;
 
+typedef enum {
+	ZEND_MEMOIZE_NONE,
+	ZEND_MEMOIZE_COMPILE,
+	ZEND_MEMOIZE_FETCH,
+} zend_memoize_mode;
+
 struct _zend_compiler_globals {
 	zend_stack loop_var_stack;
 
@@ -129,7 +135,7 @@ struct _zend_compiler_globals {
 
 	zend_stack delayed_oplines_stack;
 	HashTable *memoized_exprs;
-	int memoize_mode;
+	zend_memoize_mode memoize_mode;
 
 	void   *map_ptr_real_base;
 	void   *map_ptr_base;
diff --git a/Zend/zend_stack.c b/Zend/zend_stack.c
index f587452bb7d59..5d9cc166367e7 100644
--- a/Zend/zend_stack.c
+++ b/Zend/zend_stack.c
@@ -119,7 +119,7 @@ ZEND_API void zend_stack_apply(zend_stack *stack, int type, int (*apply_function
 }
 
 
-ZEND_API void zend_stack_apply_with_argument(zend_stack *stack, int type, int (*apply_function)(void *element, void *arg), void *arg)
+ZEND_API void zend_stack_apply_with_argument(zend_stack *stack, zend_stack_apply_direction type, int (*apply_function)(void *element, void *arg), void *arg)
 {
 	int i;
 
diff --git a/Zend/zend_stack.h b/Zend/zend_stack.h
index c0a325b778870..68c3621533f92 100644
--- a/Zend/zend_stack.h
+++ b/Zend/zend_stack.h
@@ -28,6 +28,11 @@ typedef struct _zend_stack {
 
 #define STACK_BLOCK_SIZE 16
 
+typedef enum {
+	ZEND_STACK_APPLY_TOPDOWN,
+	ZEND_STACK_APPLY_BOTTOMUP,
+} zend_stack_apply_direction;
+
 BEGIN_EXTERN_C()
 ZEND_API void zend_stack_init(zend_stack *stack, int size);
 ZEND_API int zend_stack_push(zend_stack *stack, const void *element);
@@ -39,11 +44,8 @@ ZEND_API void zend_stack_destroy(zend_stack *stack);
 ZEND_API void *zend_stack_base(const zend_stack *stack);
 ZEND_API int zend_stack_count(const zend_stack *stack);
 ZEND_API void zend_stack_apply(zend_stack *stack, int type, int (*apply_function)(void *element));
-ZEND_API void zend_stack_apply_with_argument(zend_stack *stack, int type, int (*apply_function)(void *element, void *arg), void *arg);
+ZEND_API void zend_stack_apply_with_argument(zend_stack *stack, zend_stack_apply_direction type, int (*apply_function)(void *element, void *arg), void *arg);
 ZEND_API void zend_stack_clean(zend_stack *stack, void (*func)(void *), bool free_elements);
 END_EXTERN_C()
 
-#define ZEND_STACK_APPLY_TOPDOWN	1
-#define ZEND_STACK_APPLY_BOTTOMUP	2
-
 #endif /* ZEND_STACK_H */