diff --git a/Zend/Optimizer/dce.c b/Zend/Optimizer/dce.c
index 7bb5020c5a5..4aca34c943c 100644
--- a/Zend/Optimizer/dce.c
+++ b/Zend/Optimizer/dce.c
@@ -22,7 +22,6 @@
 #include "Optimizer/zend_ssa.h"
 #include "Optimizer/zend_func_info.h"
 #include "Optimizer/zend_call_graph.h"
-#include "zend_arena.h"
 #include "zend_bitset.h"
 
 /* This pass implements a form of dead code elimination (DCE). The algorithm optimistically assumes
diff --git a/Zend/Optimizer/sccp.c b/Zend/Optimizer/sccp.c
index 45ae7627376..9373ad2adc6 100644
--- a/Zend/Optimizer/sccp.c
+++ b/Zend/Optimizer/sccp.c
@@ -18,11 +18,8 @@
 */
 
 #include "zend_API.h"
-#include "zend_arena.h"
-#include "zend_multiply.h" // for zend_safe_address_guarded()
 #include "zend_exceptions.h"
 #include "zend_ini.h"
-#include "zend_optimizer.h"
 #include "zend_type_info.h"
 #include "Optimizer/zend_optimizer_internal.h"
 #include "Optimizer/zend_call_graph.h"
diff --git a/Zend/Optimizer/scdf.c b/Zend/Optimizer/scdf.c
index fb7337a1009..54925e8287b 100644
--- a/Zend/Optimizer/scdf.c
+++ b/Zend/Optimizer/scdf.c
@@ -16,9 +16,8 @@
    +----------------------------------------------------------------------+
 */
 
-#include "Optimizer/scdf.h"
 #include "Optimizer/zend_optimizer_internal.h"
-#include "zend_arena.h"
+#include "Optimizer/scdf.h"
 
 /* This defines a generic framework for sparse conditional dataflow propagation. The algorithm is
  * based on "Sparse conditional constant propagation" by Wegman and Zadeck. We're using a
diff --git a/Zend/Optimizer/scdf.h b/Zend/Optimizer/scdf.h
index f72b2ca151f..840a99065bc 100644
--- a/Zend/Optimizer/scdf.h
+++ b/Zend/Optimizer/scdf.h
@@ -20,11 +20,6 @@
 #define _SCDF_H
 
 #include "zend_bitset.h"
-#include "zend_long.h"
-#include "zend_ssa.h"
-
-typedef struct _zend_op_array zend_op_array;
-typedef struct _zend_optimizer_ctx zend_optimizer_ctx;
 
 typedef struct _scdf_ctx {
 	zend_op_array *op_array;
diff --git a/Zend/Optimizer/zend_call_graph.c b/Zend/Optimizer/zend_call_graph.c
index 70342c06547..c2b7b00cbee 100644
--- a/Zend/Optimizer/zend_call_graph.c
+++ b/Zend/Optimizer/zend_call_graph.c
@@ -16,11 +16,15 @@
    +----------------------------------------------------------------------+
 */
 
-#include "zend_call_graph.h"
-#include "zend_arena.h"
-#include "zend_bitset.h"
-#include "zend_func_info.h"
+#include "zend_compile.h"
+#include "zend_extensions.h"
+#include "Optimizer/zend_optimizer.h"
 #include "zend_optimizer_internal.h"
+#include "zend_inference.h"
+#include "zend_call_graph.h"
+#include "zend_func_info.h"
+#include "zend_inference.h"
+#include "zend_call_graph.h"
 
 static void zend_op_array_calc(zend_op_array *op_array, void *context)
 {
diff --git a/Zend/Optimizer/zend_call_graph.h b/Zend/Optimizer/zend_call_graph.h
index 7dd6430dd4e..5b1634d561d 100644
--- a/Zend/Optimizer/zend_call_graph.h
+++ b/Zend/Optimizer/zend_call_graph.h
@@ -20,9 +20,8 @@
 #define ZEND_CALL_GRAPH_H
 
 #include "zend_ssa.h"
-
-typedef struct _zend_func_info zend_func_info;
-typedef struct _zend_call_info zend_call_info;
+#include "zend_func_info.h"
+#include "zend_optimizer.h"
 
 typedef struct _zend_send_arg_info {
 	zend_op                *opline;
diff --git a/Zend/Optimizer/zend_cfg.c b/Zend/Optimizer/zend_cfg.c
index e99051542c4..6d538f71316 100644
--- a/Zend/Optimizer/zend_cfg.c
+++ b/Zend/Optimizer/zend_cfg.c
@@ -16,12 +16,13 @@
    +----------------------------------------------------------------------+
 */
 
+#include "zend_compile.h"
 #include "zend_cfg.h"
-#include "zend_func_info.h" // for ZEND_FUNC_FREE_LOOP_VAR
-#include "zend_globals.h" // struct _zend_executor_globals
-#include "zend_globals_macros.h" // for EG()
-#include "zend_optimizer_internal.h"
+#include "zend_func_info.h"
 #include "zend_worklist.h"
+#include "zend_optimizer.h"
+#include "zend_optimizer_internal.h"
+#include "zend_sort.h"
 
 static void zend_mark_reachable(zend_op *opcodes, zend_cfg *cfg, zend_basic_block *b) /* {{{ */
 {
diff --git a/Zend/Optimizer/zend_cfg.h b/Zend/Optimizer/zend_cfg.h
index cf0a591b363..93d45506068 100644
--- a/Zend/Optimizer/zend_cfg.h
+++ b/Zend/Optimizer/zend_cfg.h
@@ -19,13 +19,6 @@
 #ifndef ZEND_CFG_H
 #define ZEND_CFG_H
 
-#include "zend_portability.h" // for BEGIN_EXTERN_C
-
-#include <stdint.h>
-
-typedef struct _zend_arena zend_arena;
-typedef struct _zend_op_array zend_op_array;
-
 /* zend_basic_block.flags */
 #define ZEND_BB_START            (1<<0)  /* first block            */
 #define ZEND_BB_FOLLOW           (1<<1)  /* follows the next block */
diff --git a/Zend/Optimizer/zend_inference.c b/Zend/Optimizer/zend_inference.c
index 532e8985688..1aeaa02f7b3 100644
--- a/Zend/Optimizer/zend_inference.c
+++ b/Zend/Optimizer/zend_inference.c
@@ -16,15 +16,13 @@
    +----------------------------------------------------------------------+
 */
 
+#include "zend_compile.h"
+#include "zend_generators.h"
 #include "zend_inference.h"
-#include "zend_closures.h" // for zend_ce_closure
-#include "zend_generators.h" // for zend_ce_generator
 #include "zend_func_info.h"
-#include "zend_globals.h" // struct _zend_executor_globals
-#include "zend_globals_macros.h" // for EG()
 #include "zend_call_graph.h"
+#include "zend_closures.h"
 #include "zend_worklist.h"
-#include "zend_optimizer.h"
 #include "zend_optimizer_internal.h"
 
 /* The used range inference algorithm is described in:
diff --git a/Zend/Optimizer/zend_inference.h b/Zend/Optimizer/zend_inference.h
index 65b48ee6a86..f27c5ecdc48 100644
--- a/Zend/Optimizer/zend_inference.h
+++ b/Zend/Optimizer/zend_inference.h
@@ -19,11 +19,12 @@
 #ifndef ZEND_INFERENCE_H
 #define ZEND_INFERENCE_H
 
-#include "zend_cfg.h" // for CRT_CONSTANT()
-#include "zend_compile.h" // for struct _zend_op
-#include "zend_portability.h" // for BEGIN_EXTERN_C
+#include "zend_optimizer.h"
 #include "zend_ssa.h"
-#include "zend_type_info.h" // for MAY_BE_*
+#include "zend_bitset.h"
+
+/* Bitmask for type inference (zend_ssa_var_info.type) */
+#include "zend_type_info.h"
 
 #define MAY_BE_PACKED_GUARD         (1<<27) /* needs packed array guard */
 #define MAY_BE_CLASS_GUARD          (1<<27) /* needs class guard */
diff --git a/Zend/Optimizer/zend_optimizer.c b/Zend/Optimizer/zend_optimizer.c
index dcbb355ff99..b5841159bf1 100644
--- a/Zend/Optimizer/zend_optimizer.c
+++ b/Zend/Optimizer/zend_optimizer.c
@@ -21,16 +21,17 @@
 
 #include "Optimizer/zend_optimizer.h"
 #include "Optimizer/zend_optimizer_internal.h"
-#include "php_globals.h" // for PG()
-#include "zend_API.h" // for ZVAL_EMPTY_STRING()
-#include "zend_arena.h"
-#include "zend_call_graph.h" // for struct _zend_func_info
-#include "zend_dump.h" // for zend_dump_op_array()
-#include "zend_inference.h" // for OP1_INFO(), ...
-#include "zend_ini.h"
-#include "zend_observer.h"
-#include "zend_virtual_cwd.h" //for IS_ABSOLUTE_PATH()
+#include "zend_API.h"
+#include "zend_constants.h"
+#include "zend_execute.h"
 #include "zend_vm.h"
+#include "zend_cfg.h"
+#include "zend_func_info.h"
+#include "zend_call_graph.h"
+#include "zend_inference.h"
+#include "zend_dump.h"
+#include "php.h"
+#include "zend_observer.h"
 
 #ifndef ZEND_OPTIMIZER_MAX_REGISTERED_PASSES
 # define ZEND_OPTIMIZER_MAX_REGISTERED_PASSES 32
diff --git a/Zend/Optimizer/zend_optimizer.h b/Zend/Optimizer/zend_optimizer.h
index ae794b1ae66..16bfd75520d 100644
--- a/Zend/Optimizer/zend_optimizer.h
+++ b/Zend/Optimizer/zend_optimizer.h
@@ -22,11 +22,8 @@
 #ifndef ZEND_OPTIMIZER_H
 #define ZEND_OPTIMIZER_H
 
-#include "zend_compile.h" // for zend_op_array
-#include "zend_hash.h"
-#include "zend_portability.h" // for BEGIN_EXTERN_C
-
-typedef struct _zend_string zend_string;
+#include "zend.h"
+#include "zend_compile.h"
 
 #define ZEND_OPTIMIZER_PASS_1		(1<<0)   /* Simple local optimizations   */
 #define ZEND_OPTIMIZER_PASS_2		(1<<1)   /*                              */
diff --git a/Zend/Optimizer/zend_ssa.c b/Zend/Optimizer/zend_ssa.c
index 84f0d4d260f..67165a9b26d 100644
--- a/Zend/Optimizer/zend_ssa.c
+++ b/Zend/Optimizer/zend_ssa.c
@@ -17,13 +17,12 @@
    +----------------------------------------------------------------------+
 */
 
-#include "zend_ssa.h"
-#include "zend_arena.h"
-#include "zend_optimizer_internal.h"
+#include "zend_compile.h"
 #include "zend_dfg.h"
+#include "zend_ssa.h"
 #include "zend_dump.h"
-#include "zend_inference.h" // for zend_sub_will_overflow()
-#include "zend_type_info.h" // for MAY_BE_REF
+#include "zend_inference.h"
+#include "Optimizer/zend_optimizer_internal.h"
 
 static bool dominates(const zend_basic_block *blocks, int a, int b) {
 	while (blocks[b].level > blocks[a].level) {
diff --git a/Zend/Optimizer/zend_ssa.h b/Zend/Optimizer/zend_ssa.h
index 035cce5cae2..9fde352c79c 100644
--- a/Zend/Optimizer/zend_ssa.h
+++ b/Zend/Optimizer/zend_ssa.h
@@ -19,14 +19,8 @@
 #ifndef ZEND_SSA_H
 #define ZEND_SSA_H
 
+#include "zend_optimizer.h"
 #include "zend_cfg.h"
-#include "zend_compile.h" // for struct _zend_op
-#include "zend_long.h"
-#include "zend_portability.h" // for BEGIN_EXTERN_C
-#include "zend_types.h" // for zend_result
-
-typedef struct _zend_class_entry zend_class_entry;
-typedef struct _zend_script zend_script;
 
 typedef struct _zend_ssa_range {
 	zend_long              min;
diff --git a/Zend/zend_arena.h b/Zend/zend_arena.h
index 45ef617cf19..a44082e52fb 100644
--- a/Zend/zend_arena.h
+++ b/Zend/zend_arena.h
@@ -19,10 +19,7 @@
 #ifndef _ZEND_ARENA_H_
 #define _ZEND_ARENA_H_
 
-#include "zend_multiply.h" // for zend_safe_address()
-#include "zend.h" // for zend_error()
-
-#include <stddef.h> // for size_t
+#include "zend.h"
 
 #ifndef ZEND_TRACK_ARENA_ALLOC
 
diff --git a/Zend/zend_bitset.h b/Zend/zend_bitset.h
index 0a573852a49..fdb6ab79a1e 100644
--- a/Zend/zend_bitset.h
+++ b/Zend/zend_bitset.h
@@ -19,13 +19,6 @@
 #ifndef _ZEND_BITSET_H_
 #define _ZEND_BITSET_H_
 
-#include "zend_portability.h" // for zend_always_inline
-
-#include "zend_long.h"
-
-#include <stdint.h>
-#include <string.h>
-
 typedef zend_ulong *zend_bitset;
 
 #define ZEND_BITSET_ELM_SIZE sizeof(zend_ulong)
diff --git a/Zend/zend_build.h b/Zend/zend_build.h
index 795f2fa9fd5..c604fb311a7 100644
--- a/Zend/zend_build.h
+++ b/Zend/zend_build.h
@@ -19,12 +19,6 @@
 #ifndef ZEND_BUILD_H
 #define ZEND_BUILD_H
 
-#ifdef PHP_WIN32
-#include "config.w32.h"
-#else
-#include "php_config.h"
-#endif
-
 #define ZEND_TOSTR_(x) #x
 #define ZEND_TOSTR(x) ZEND_TOSTR_(x)
 
diff --git a/Zend/zend_extensions.c b/Zend/zend_extensions.c
index 4e6fe95917d..1f3687642ab 100644
--- a/Zend/zend_extensions.c
+++ b/Zend/zend_extensions.c
@@ -18,10 +18,7 @@
 */
 
 #include "zend_extensions.h"
-#include "zend_arena.h"
-#include "zend_globals.h" // for struct _zend_compiler_globals
-#include "zend_globals_macros.h" // for CG()
-#include "zend_system_id.h" // for zend_add_system_entropy()
+#include "zend_system_id.h"
 
 ZEND_API zend_llist zend_extensions;
 ZEND_API uint32_t zend_extension_flags = 0;
diff --git a/Zend/zend_extensions.h b/Zend/zend_extensions.h
index ff28a14509a..14ba9054d9b 100644
--- a/Zend/zend_extensions.h
+++ b/Zend/zend_extensions.h
@@ -20,15 +20,8 @@
 #ifndef ZEND_EXTENSIONS_H
 #define ZEND_EXTENSIONS_H
 
-#include "zend_build.h" // for ZEND_TOSTR()
-#include "zend_portability.h" // for BEGIN_EXTERN_C
-#include "zend_types.h" // for zend_result
-
-#include <stddef.h> // for size_t
-
-typedef struct _zend_execute_data zend_execute_data;
-typedef struct _zend_op_array zend_op_array;
-typedef struct _zend_llist zend_llist;
+#include "zend_compile.h"
+#include "zend_build.h"
 
 /*
 The constants below are derived from ext/opcache/ZendAccelerator.h
diff --git a/Zend/zend_float.c b/Zend/zend_float.c
index ca2ed83282d..90af0c4a5f9 100644
--- a/Zend/zend_float.c
+++ b/Zend/zend_float.c
@@ -16,9 +16,9 @@
    +----------------------------------------------------------------------+
 */
 
+#include "zend.h"
+#include "zend_compile.h"
 #include "zend_float.h"
-#include "zend_globals.h" // struct _zend_executor_globals
-#include "zend_globals_macros.h" // for EG()
 
 ZEND_API void zend_init_fpu(void) /* {{{ */
 {
diff --git a/Zend/zend_float.h b/Zend/zend_float.h
index d4d67592a5f..c8e91122a35 100644
--- a/Zend/zend_float.h
+++ b/Zend/zend_float.h
@@ -19,8 +19,6 @@
 #ifndef ZEND_FLOAT_H
 #define ZEND_FLOAT_H
 
-#include "zend_portability.h" // for BEGIN_EXTERN_C
-
 BEGIN_EXTERN_C()
 
 /*
diff --git a/Zend/zend_long.h b/Zend/zend_long.h
index f2d3ee81bd6..3796f1c5aba 100644
--- a/Zend/zend_long.h
+++ b/Zend/zend_long.h
@@ -19,12 +19,6 @@
 #ifndef ZEND_LONG_H
 #define ZEND_LONG_H
 
-#ifdef PHP_WIN32
-#include "config.w32.h"
-#else
-#include "php_config.h" // for SIZEOF_SIZE_T
-#endif
-
 #include <inttypes.h>
 #include <stdint.h>
 
diff --git a/Zend/zend_map_ptr.h b/Zend/zend_map_ptr.h
index 0ab1a357eec..aa726e0cdd3 100644
--- a/Zend/zend_map_ptr.h
+++ b/Zend/zend_map_ptr.h
@@ -19,7 +19,7 @@
 #ifndef ZEND_MAP_PTR_H
 #define ZEND_MAP_PTR_H
 
-#include "zend_portability.h" // for BEGIN_EXTERN_C
+#include "zend_portability.h"
 
 #define ZEND_MAP_PTR_KIND_PTR           0
 #define ZEND_MAP_PTR_KIND_PTR_OR_OFFSET 1
@@ -69,8 +69,6 @@
 # error "Unknown ZEND_MAP_PTR_KIND"
 #endif
 
-typedef struct _zend_string zend_string;
-
 BEGIN_EXTERN_C()
 
 ZEND_API void  zend_map_ptr_reset(void);
diff --git a/Zend/zend_multiply.h b/Zend/zend_multiply.h
index 417ee9990a8..a99e858bd77 100644
--- a/Zend/zend_multiply.h
+++ b/Zend/zend_multiply.h
@@ -17,12 +17,11 @@
    +----------------------------------------------------------------------+
 */
 
+#include "zend_portability.h"
+
 #ifndef ZEND_MULTIPLY_H
 #define ZEND_MULTIPLY_H
 
-#include "zend_portability.h"
-#include "zend.h" // for zend_error_noreturn()
-
 #if PHP_HAVE_BUILTIN_SMULL_OVERFLOW && SIZEOF_LONG == SIZEOF_ZEND_LONG
 
 #define ZEND_SIGNED_MULTIPLY_LONG(a, b, lval, dval, usedval) do {	\
diff --git a/Zend/zend_stream.c b/Zend/zend_stream.c
index 41b89d1d86b..8e11841ad26 100644
--- a/Zend/zend_stream.c
+++ b/Zend/zend_stream.c
@@ -19,11 +19,9 @@
    +----------------------------------------------------------------------+
 */
 
+#include "zend.h"
+#include "zend_compile.h"
 #include "zend_stream.h"
-#include "zend_globals.h" // struct _zend_compiler_globals
-#include "zend_globals_macros.h" // for CG()
-#include "zend_string.h"
-#include "zend.h" // for zend_stream_open_function
 
 ZEND_DLIMPORT int isatty(int fd);
 
diff --git a/Zend/zend_stream.h b/Zend/zend_stream.h
index 22541bf8d92..047719e175a 100644
--- a/Zend/zend_stream.h
+++ b/Zend/zend_stream.h
@@ -22,16 +22,9 @@
 #ifndef ZEND_STREAM_H
 #define ZEND_STREAM_H
 
-#include "zend_portability.h" // for BEGIN_EXTERN_C
-#include "zend_types.h" // for zend_uchar
-
-#include <stdbool.h>
-#include <stdio.h> // for FILE
-#include <sys/types.h> // for ssize_t
+#include <sys/types.h>
 #include <sys/stat.h>
 
-typedef struct _zend_string zend_string;
-
 /* Lightweight stream implementation for the ZE scanners.
  * These functions are private to the engine.
  * */
diff --git a/Zend/zend_system_id.c b/Zend/zend_system_id.c
index deb3e27823e..8390bba8b0f 100644
--- a/Zend/zend_system_id.c
+++ b/Zend/zend_system_id.c
@@ -15,10 +15,11 @@
    +----------------------------------------------------------------------+
  */
 
+#include "php.h"
 #include "zend_system_id.h"
-#include "zend_extensions.h" // for ZEND_EXTENSION_BUILD_ID
+#include "zend_extensions.h"
 #include "ext/standard/md5.h"
-#include "ext/hash/php_hash.h" // for php_hash_bin2hex()
+#include "ext/hash/php_hash.h"
 
 ZEND_API char zend_system_id[32];
 
diff --git a/Zend/zend_system_id.h b/Zend/zend_system_id.h
index 3c008637694..60514e15a09 100644
--- a/Zend/zend_system_id.h
+++ b/Zend/zend_system_id.h
@@ -17,9 +17,6 @@
 #ifndef ZEND_SYSTEM_ID_H
 #define ZEND_SYSTEM_ID_H
 
-#include "zend_portability.h" // for BEGIN_EXTERN_C
-#include "zend_types.h" // for ZEND_RESULT_CODE
-
 BEGIN_EXTERN_C()
 /* True global; Write-only during MINIT/startup */
 extern ZEND_API char zend_system_id[32];
diff --git a/Zend/zend_types.h b/Zend/zend_types.h
index 888c35482a4..e6505d8b62a 100644
--- a/Zend/zend_types.h
+++ b/Zend/zend_types.h
@@ -24,8 +24,6 @@
 
 #include "zend_portability.h"
 #include "zend_long.h"
-#include "zend_type_info.h" // for MAY_BE_*
-
 #include <stdbool.h>
 
 #ifdef __SSE2__
diff --git a/ext/opcache/zend_accelerator_hash.c b/ext/opcache/zend_accelerator_hash.c
index 2354409fd51..676ed32ce8f 100644
--- a/ext/opcache/zend_accelerator_hash.c
+++ b/ext/opcache/zend_accelerator_hash.c
@@ -19,7 +19,9 @@
    +----------------------------------------------------------------------+
 */
 
+#include "ZendAccelerator.h"
 #include "zend_accelerator_hash.h"
+#include "zend_hash.h"
 #include "zend_shared_alloc.h"
 
 /* Generated on an Octa-ALPHA 300MHz CPU & 2.5GB RAM monster */
diff --git a/ext/opcache/zend_accelerator_hash.h b/ext/opcache/zend_accelerator_hash.h
index c868427491e..755d3f13ec5 100644
--- a/ext/opcache/zend_accelerator_hash.h
+++ b/ext/opcache/zend_accelerator_hash.h
@@ -22,12 +22,7 @@
 #ifndef ZEND_ACCELERATOR_HASH_H
 #define ZEND_ACCELERATOR_HASH_H
 
-#include "zend_long.h"
-#include "zend_portability.h" // for BEGIN_EXTERN_C
-
-#include <stdint.h>
-
-typedef struct _zend_string zend_string;
+#include "zend.h"
 
 /*
 	zend_accel_hash - is a hash table allocated in shared memory and
diff --git a/ext/standard/md5.c b/ext/standard/md5.c
index b7cff21d024..899ff6aaeec 100644
--- a/ext/standard/md5.c
+++ b/ext/standard/md5.c
@@ -16,6 +16,7 @@
    +----------------------------------------------------------------------+
 */
 
+#include "php.h"
 #include "md5.h"
 
 PHPAPI void make_digest(char *md5str, const unsigned char *digest) /* {{{ */
diff --git a/ext/standard/md5.h b/ext/standard/md5.h
index 5814142f196..0003a934be6 100644
--- a/ext/standard/md5.h
+++ b/ext/standard/md5.h
@@ -18,10 +18,6 @@
 #ifndef MD5_H
 #define MD5_H
 
-#include "php.h" // for PHPAPI
-
-#include <stdint.h>
-
 PHPAPI void make_digest(char *md5str, const unsigned char *digest);
 PHPAPI void make_digest_ex(char *md5str, const unsigned char *digest, int len);
 
diff --git a/main/php_globals.h b/main/php_globals.h
index 9a9653f4c1e..cbf0271c7b7 100644
--- a/main/php_globals.h
+++ b/main/php_globals.h
@@ -17,7 +17,6 @@
 #ifndef PHP_GLOBALS_H
 #define PHP_GLOBALS_H
 
-#include "php.h" // for PHPAPI
 #include "zend_globals.h"
 
 typedef struct _php_core_globals php_core_globals;