diff --git a/UPGRADING b/UPGRADING
index 9c0909963aeb..aa3e80f447ff 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -45,6 +45,10 @@ PHP 8.4 UPGRADE NOTES
     object. This is no longer possible, and cloning a DOMXPath object now throws
     an error.
 
+- FFI:
+  . Using FFI::load() during preloading ("opcache.preload") is not supported
+    anymore. Use "ffi.preload" instead.
+
 - MBString:
   . mb_encode_numericentity() and mb_decode_numericentity() now check that
     the $map is only composed of integers, if not a ValueError is thrown.
diff --git a/UPGRADING.INTERNALS b/UPGRADING.INTERNALS
index 7463182e083d..6b2ff771f885 100644
--- a/UPGRADING.INTERNALS
+++ b/UPGRADING.INTERNALS
@@ -40,6 +40,12 @@ PHP 8.4 INTERNALS UPGRADE NOTES
 * The inet_aton() and win32/inet.h on Windows have been removed. Use Windows
   native inet_pton() from ws2tcpip.h.
 
+* It is recommended that extensions initializing external libraries or starting
+  threads during module startup (MINIT) do so in the child startup hook (CHINIT)
+  instead. A child startup hook can be declared by using the
+  PHP_MODULE_SET_CHINIT_FUNC() macro during module startup. See
+  ext/curl/interface.c for an example.
+
 ========================
 2. Build system changes
 ========================
@@ -147,3 +153,7 @@ PHP 8.4 INTERNALS UPGRADE NOTES
 ========================
 5. SAPI changes
 ========================
+
+* SAPIs must call php_module_child_startup() once per request-handling process,
+  any time before handling the first request of the process, and must not fork
+  (without exec()) after that.
diff --git a/Zend/zend_API.c b/Zend/zend_API.c
index 2a16f24250eb..f9ba92ba8c73 100644
--- a/Zend/zend_API.c
+++ b/Zend/zend_API.c
@@ -34,6 +34,16 @@
 #include "zend_observer.h"
 
 #include <stdarg.h>
+#if ZEND_DEBUG
+# if __linux__
+#  include <sys/types.h>
+#  include <dirent.h>
+# elif __APPLE__
+#  include <mach/mach_init.h>
+#  include <mach/task.h>
+#  include <mach/vm_map.h>
+# endif /* __APPLE__ */
+#endif
 
 /* these variables are true statics/globals, and have to be mutex'ed on every access */
 ZEND_API HashTable module_registry;
@@ -2292,6 +2302,64 @@ ZEND_API void add_property_zval_ex(zval *arg, const char *key, size_t key_len, z
 }
 /* }}} */
 
+#if ZEND_DEBUG
+# if __linux__
+static int zend_thread_count(void)
+{
+	pid_t pid = getpid();
+	char path[64];
+	int len = snprintf(path, sizeof(path), "/proc/%d/task", (int)pid);
+	if (len == -1 || len >= sizeof(path)) {
+		return -1;
+	}
+
+	DIR *d = opendir(path);
+	if (d == NULL) {
+		return -1;
+	}
+
+	struct dirent *entry;
+	int nthreads = 0;
+	while ((entry = readdir(d))){
+		nthreads++;
+	}
+
+	closedir(d);
+
+	return nthreads;
+}
+# elif __APPLE__
+static int zend_thread_count(void)
+{
+	pid_t pid = getpid();
+	mach_port_t me = mach_task_self();
+	mach_port_t task;
+	kern_return_t res;
+	thread_array_t threads;
+	mach_msg_type_number_t nthreads;
+
+	res = task_for_pid(me, pid, &task);
+	if (res != KERN_SUCCESS) {
+		return -1;
+	}
+
+	res = task_threads(task, &threads, &nthreads);
+	if (res != KERN_SUCCESS) {
+		return -1;
+	}
+
+	vm_deallocate(me, (vm_address_t)threads, nthreads * sizeof(*threads));
+
+	return (int) nthreads;
+}
+# else
+static int zend_thread_count(void)
+{
+	return 0;
+}
+# endif /* __APPLE__ */
+#endif
+
 ZEND_API zend_result zend_startup_module_ex(zend_module_entry *module) /* {{{ */
 {
 	size_t name_len;
@@ -2338,6 +2406,9 @@ ZEND_API zend_result zend_startup_module_ex(zend_module_entry *module) /* {{{ */
 #endif
 	}
 	if (module->module_startup_func) {
+#if ZEND_DEBUG
+		int thread_count = zend_thread_count();
+#endif
 		EG(current_module) = module;
 		if (module->module_startup_func(module->type, module->module_number)==FAILURE) {
 			zend_error_noreturn(E_CORE_ERROR,"Unable to start %s module", module->name);
@@ -2345,7 +2416,19 @@ ZEND_API zend_result zend_startup_module_ex(zend_module_entry *module) /* {{{ */
 			return FAILURE;
 		}
 		EG(current_module) = NULL;
+#if ZEND_DEBUG
+		if (zend_thread_count() > thread_count) {
+			zend_error_noreturn(E_CORE_ERROR,
+					"Thread count increased during the initialization of %s"
+					" module. This is unsafe as the process may be forked after"
+					" initialization. Modules whishing to start threads should"
+					" do so in child_startup_func.",
+					module->name);
+			abort();
+		}
+#endif
 	}
+
 	return SUCCESS;
 }
 /* }}} */
@@ -2491,6 +2574,40 @@ ZEND_API void zend_destroy_modules(void) /* {{{ */
 }
 /* }}} */
 
+ZEND_API void zend_child_startup_modules(void) /* {{{ */
+{
+	zend_module_entry *module;
+
+	ZEND_HASH_MAP_FOREACH_PTR(&module_registry, module) {
+		if (module->child_startup_func) {
+			if (module->child_startup_func(module->type, module->module_number)==FAILURE) {
+				zend_error(E_CORE_ERROR, "child_startup() for %s module failed", module->name);
+				exit(1);
+			}
+		}
+	} ZEND_HASH_FOREACH_END();
+}
+/* }}} */
+
+ZEND_API void zend_module_set_child_startup_func(INIT_FUNC_ARGS, zend_result (*child_startup_func)(INIT_FUNC_ARGS)) /* {{{ */
+{
+	if (!EG(current_module)) {
+		zend_error(E_CORE_ERROR, "Can not set child startup func after startup");
+		abort();
+	}
+
+	if (EG(current_module)->module_number != module_number) {
+		zend_error(E_CORE_ERROR,
+				"Invalid module_number passed to zend_set_child_startup_func"
+				" during statup of %s module",
+				EG(current_module)->name);
+		abort();
+	}
+
+	EG(current_module)->child_startup_func = child_startup_func;
+}
+/* }}} */
+
 ZEND_API zend_module_entry* zend_register_module_ex(zend_module_entry *module, int module_type) /* {{{ */
 {
 	size_t name_len;
diff --git a/Zend/zend_API.h b/Zend/zend_API.h
index aa085c70d9bb..557ddab878a5 100644
--- a/Zend/zend_API.h
+++ b/Zend/zend_API.h
@@ -221,6 +221,7 @@ typedef struct _zend_fcall_info_cache {
 /* Name macros */
 #define ZEND_MODULE_STARTUP_N(module)       zm_startup_##module
 #define ZEND_MODULE_SHUTDOWN_N(module)		zm_shutdown_##module
+#define ZEND_MODULE_CHILD_STARTUP_N(module) zm_child_startup_##module
 #define ZEND_MODULE_ACTIVATE_N(module)		zm_activate_##module
 #define ZEND_MODULE_DEACTIVATE_N(module)	zm_deactivate_##module
 #define ZEND_MODULE_POST_ZEND_DEACTIVATE_N(module)	zm_post_zend_deactivate_##module
@@ -231,6 +232,7 @@ typedef struct _zend_fcall_info_cache {
 /* Declaration macros */
 #define ZEND_MODULE_STARTUP_D(module)		zend_result ZEND_MODULE_STARTUP_N(module)(INIT_FUNC_ARGS)
 #define ZEND_MODULE_SHUTDOWN_D(module)		zend_result ZEND_MODULE_SHUTDOWN_N(module)(SHUTDOWN_FUNC_ARGS)
+#define ZEND_MODULE_CHILD_STARTUP_D(module)	zend_result ZEND_MODULE_CHILD_STARTUP_N(module)(INIT_FUNC_ARGS)
 #define ZEND_MODULE_ACTIVATE_D(module)		zend_result ZEND_MODULE_ACTIVATE_N(module)(INIT_FUNC_ARGS)
 #define ZEND_MODULE_DEACTIVATE_D(module)	zend_result ZEND_MODULE_DEACTIVATE_N(module)(SHUTDOWN_FUNC_ARGS)
 #define ZEND_MODULE_POST_ZEND_DEACTIVATE_D(module)	zend_result ZEND_MODULE_POST_ZEND_DEACTIVATE_N(module)(void)
@@ -243,6 +245,9 @@ typedef struct _zend_fcall_info_cache {
 	ZEND_DLEXPORT zend_module_entry *get_module(void) { return &name##_module_entry; }\
     END_EXTERN_C()
 
+#define ZEND_MODULE_SET_CHILD_STARTUP_FUNC(func) \
+	zend_module_set_child_startup_func(INIT_FUNC_ARGS_PASSTHRU, func)
+
 #define ZEND_BEGIN_MODULE_GLOBALS(module_name)		\
 	typedef struct _zend_##module_name##_globals {
 #define ZEND_END_MODULE_GLOBALS(module_name)		\
@@ -384,6 +389,8 @@ ZEND_API zend_result zend_startup_module_ex(zend_module_entry *module);
 ZEND_API void zend_startup_modules(void);
 ZEND_API void zend_collect_module_handlers(void);
 ZEND_API void zend_destroy_modules(void);
+ZEND_API void zend_child_startup_modules(void);
+ZEND_API void zend_module_set_child_startup_func(INIT_FUNC_ARGS, zend_result (*child_startup_func)(INIT_FUNC_ARGS));
 ZEND_API void zend_check_magic_method_implementation(
 		const zend_class_entry *ce, const zend_function *fptr, zend_string *lcname, int error_type);
 ZEND_API void zend_add_magic_method(zend_class_entry *ce, zend_function *fptr, zend_string *lcname);
diff --git a/Zend/zend_modules.h b/Zend/zend_modules.h
index f3f6ca826817..ef8101df40b5 100644
--- a/Zend/zend_modules.h
+++ b/Zend/zend_modules.h
@@ -46,7 +46,7 @@
 
 #define ZEND_MODULE_BUILD_ID "API" ZEND_TOSTR(ZEND_MODULE_API_NO) ZEND_BUILD_TS ZEND_BUILD_DEBUG ZEND_BUILD_SYSTEM ZEND_BUILD_EXTRA
 
-#define STANDARD_MODULE_PROPERTIES_EX 0, 0, NULL, 0, ZEND_MODULE_BUILD_ID
+#define STANDARD_MODULE_PROPERTIES_EX NULL, 0, 0, NULL, 0, ZEND_MODULE_BUILD_ID
 
 #define NO_MODULE_GLOBALS 0, NULL, NULL, NULL
 
@@ -77,8 +77,12 @@ struct _zend_module_entry {
 	const struct _zend_module_dep *deps;
 	const char *name;
 	const struct _zend_function_entry *functions;
+	/* Called once per process, excluding forked processes. This function
+	 * must not start threads. Calling external libraries from this function is
+	 * not recommended. */
 	zend_result (*module_startup_func)(INIT_FUNC_ARGS);
 	zend_result (*module_shutdown_func)(SHUTDOWN_FUNC_ARGS);
+	/* Called once per request */
 	zend_result (*request_startup_func)(INIT_FUNC_ARGS);
 	zend_result (*request_shutdown_func)(SHUTDOWN_FUNC_ARGS);
 	void (*info_func)(ZEND_MODULE_INFO_FUNC_ARGS);
@@ -92,6 +96,8 @@ struct _zend_module_entry {
 	void (*globals_ctor)(void *global);
 	void (*globals_dtor)(void *global);
 	zend_result (*post_deactivate_func)(void);
+	/* Called once per request-handling process */
+	zend_result (*child_startup_func)(INIT_FUNC_ARGS);
 	int module_started;
 	unsigned char type;
 	void *handle;
diff --git a/ext/curl/interface.c b/ext/curl/interface.c
index 60481947ddde..be9c9c0a2757 100644
--- a/ext/curl/interface.c
+++ b/ext/curl/interface.c
@@ -365,10 +365,22 @@ PHP_MINFO_FUNCTION(curl)
 }
 /* }}} */
 
+/* {{{ PHP_CHINIT_FUNCTION */
+PHP_CHINIT_FUNCTION(curl)
+{
+	if (curl_global_init(CURL_GLOBAL_DEFAULT) != CURLE_OK) {
+		return FAILURE;
+	}
+
+	return SUCCESS;
+}
+/* }}} */
+
 /* {{{ PHP_MINIT_FUNCTION */
 PHP_MINIT_FUNCTION(curl)
 {
 	REGISTER_INI_ENTRIES();
+	PHP_MODULE_SET_CHINIT_FUNC(PHP_CHINIT(curl));
 
 	register_curl_symbols(module_number);
 
@@ -390,10 +402,6 @@ PHP_MINIT_FUNCTION(curl)
 	}
 #endif
 
-	if (curl_global_init(CURL_GLOBAL_DEFAULT) != CURLE_OK) {
-		return FAILURE;
-	}
-
 	curl_ce = register_class_CurlHandle();
 	curl_ce->create_object = curl_create_object;
 	curl_ce->default_object_handlers = &curl_object_handlers;
diff --git a/ext/ffi/ffi.c b/ext/ffi/ffi.c
index f1ae201f7974..fc97f076530f 100644
--- a/ext/ffi/ffi.c
+++ b/ext/ffi/ffi.c
@@ -3537,7 +3537,7 @@ ZEND_METHOD(FFI, load) /* {{{ */
 	ZEND_PARSE_PARAMETERS_END();
 
 	if (CG(compiler_options) & ZEND_COMPILE_PRELOAD_IN_CHILD) {
-		zend_throw_error(zend_ffi_exception_ce, "FFI::load() doesn't work in conjunction with \"opcache.preload_user\". Use \"ffi.preload\" instead.");
+		zend_throw_error(zend_ffi_exception_ce, "FFI::load() doesn't work in conjunction with \"opcache.preload\". Use \"ffi.preload\" instead.");
 		RETURN_THROWS();
 	}
 
diff --git a/ext/ffi/tests/300.phpt b/ext/ffi/tests/300.phpt
deleted file mode 100644
index fbadfb9829d5..000000000000
--- a/ext/ffi/tests/300.phpt
+++ /dev/null
@@ -1,25 +0,0 @@
---TEST--
-FFI 300: FFI preloading
---EXTENSIONS--
-ffi
-opcache
-posix
---SKIPIF--
-<?php
-if (substr(PHP_OS, 0, 3) == 'WIN') die('skip not for Windows');
-if (posix_geteuid() == 0) die('skip Cannot run test as root.');
-?>
---INI--
-ffi.enable=1
-opcache.enable=1
-opcache.enable_cli=1
-opcache.optimization_level=-1
-opcache.preload={PWD}/preload.inc
-opcache.file_cache_only=0
---FILE--
-<?php
-$ffi = FFI::scope("TEST_300");
-$ffi->printf("Hello World from %s!\n", "PHP");
-?>
---EXPECT--
-Hello World from PHP!
diff --git a/ext/ffi/tests/bug78761.phpt b/ext/ffi/tests/bug78761.phpt
index fc1c66129114..c72b035f1328 100644
--- a/ext/ffi/tests/bug78761.phpt
+++ b/ext/ffi/tests/bug78761.phpt
@@ -2,15 +2,8 @@
 Bug #78761 (Zend memory heap corruption with preload and casting)
 --EXTENSIONS--
 ffi
-posix
---SKIPIF--
-<?php
-if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
-if (posix_geteuid() == 0) die('skip Cannot run test as root.');
-?>
 --INI--
-opcache.enable_cli=1
-opcache.preload={PWD}/bug78761_preload.php
+ffi.preload={PWD}/bug78761_preload.h
 --FILE--
 <?php
 try {
diff --git a/ext/ffi/tests/bug78761_preload.php b/ext/ffi/tests/bug78761_preload.php
deleted file mode 100644
index 207b7c3ec841..000000000000
--- a/ext/ffi/tests/bug78761_preload.php
+++ /dev/null
@@ -1,3 +0,0 @@
-<?php
-
-FFI::load(__DIR__ . '/bug78761_preload.h');
diff --git a/ext/opcache/ZendAccelerator.c b/ext/opcache/ZendAccelerator.c
index b9149fa1fa12..fc1ca828d51e 100644
--- a/ext/opcache/ZendAccelerator.c
+++ b/ext/opcache/ZendAccelerator.c
@@ -4667,43 +4667,33 @@ static zend_result accel_finish_startup_preload(bool in_child)
 
 static zend_result accel_finish_startup_preload_subprocess(pid_t *pid)
 {
+	struct passwd *pw = NULL;
 	uid_t euid = geteuid();
 	if (euid != 0) {
 		if (ZCG(accel_directives).preload_user
 		 && *ZCG(accel_directives).preload_user) {
 			zend_accel_error(ACCEL_LOG_WARNING, "\"opcache.preload_user\" is ignored because the current user is not \"root\"");
 		}
+	} else {
+		if (!ZCG(accel_directives).preload_user
+		 || !*ZCG(accel_directives).preload_user) {
 
-		*pid = -1;
-		return SUCCESS;
-	}
-
-	if (!ZCG(accel_directives).preload_user
-	 || !*ZCG(accel_directives).preload_user) {
-
-		bool sapi_requires_preload_user = !(strcmp(sapi_module.name, "cli") == 0
-		  || strcmp(sapi_module.name, "phpdbg") == 0);
+			bool sapi_requires_preload_user = !(strcmp(sapi_module.name, "cli") == 0
+			  || strcmp(sapi_module.name, "phpdbg") == 0);
 
-		if (!sapi_requires_preload_user) {
-			*pid = -1;
-			return SUCCESS;
+			if (sapi_requires_preload_user) {
+				zend_shared_alloc_unlock();
+				zend_accel_error_noreturn(ACCEL_LOG_FATAL, "\"opcache.preload\" requires \"opcache.preload_user\" when running under uid 0");
+				return FAILURE;
+			}
+		} else {
+			pw = getpwnam(ZCG(accel_directives).preload_user);
+			if (pw == NULL) {
+				zend_shared_alloc_unlock();
+				zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Preloading failed to getpwnam(\"%s\")", ZCG(accel_directives).preload_user);
+				return FAILURE;
+			}
 		}
-
-		zend_shared_alloc_unlock();
-		zend_accel_error_noreturn(ACCEL_LOG_FATAL, "\"opcache.preload\" requires \"opcache.preload_user\" when running under uid 0");
-		return FAILURE;
-	}
-
-	struct passwd *pw = getpwnam(ZCG(accel_directives).preload_user);
-	if (pw == NULL) {
-		zend_shared_alloc_unlock();
-		zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Preloading failed to getpwnam(\"%s\")", ZCG(accel_directives).preload_user);
-		return FAILURE;
-	}
-
-	if (pw->pw_uid == euid) {
-		*pid = -1;
-		return SUCCESS;
 	}
 
 	*pid = fork();
@@ -4714,17 +4704,19 @@ static zend_result accel_finish_startup_preload_subprocess(pid_t *pid)
 	}
 
 	if (*pid == 0) { /* children */
-		if (setgid(pw->pw_gid) < 0) {
-			zend_accel_error(ACCEL_LOG_WARNING, "Preloading failed to setgid(%d)", pw->pw_gid);
-			exit(1);
-		}
-		if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
-			zend_accel_error(ACCEL_LOG_WARNING, "Preloading failed to initgroups(\"%s\", %d)", pw->pw_name, pw->pw_uid);
-			exit(1);
-		}
-		if (setuid(pw->pw_uid) < 0) {
-			zend_accel_error(ACCEL_LOG_WARNING, "Preloading failed to setuid(%d)", pw->pw_uid);
-			exit(1);
+		if (pw != NULL && pw->pw_uid != euid) {
+			if (setgid(pw->pw_gid) < 0) {
+				zend_accel_error(ACCEL_LOG_WARNING, "Preloading failed to setgid(%d)", pw->pw_gid);
+				exit(1);
+			}
+			if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
+				zend_accel_error(ACCEL_LOG_WARNING, "Preloading failed to initgroups(\"%s\", %d)", pw->pw_name, pw->pw_uid);
+				exit(1);
+			}
+			if (setuid(pw->pw_uid) < 0) {
+				zend_accel_error(ACCEL_LOG_WARNING, "Preloading failed to setuid(%d)", pw->pw_uid);
+				exit(1);
+			}
 		}
 	}
 
@@ -4769,10 +4761,9 @@ static zend_result accel_finish_startup(void)
 		return FAILURE;
 	}
 
-	if (pid == -1) { /* no subprocess was needed */
-		/* The called function unlocks the shared alloc lock */
-		return accel_finish_startup_preload(false);
-	} else if (pid == 0) { /* subprocess */
+	if (pid == 0) { /* subprocess */
+		ZEND_ASSERT(sapi_module.child_startup);
+		sapi_module.child_startup(&sapi_module);
 		const zend_result ret = accel_finish_startup_preload(true);
 
 		exit(ret == SUCCESS ? 0 : 1);
diff --git a/main/SAPI.h b/main/SAPI.h
index 284f4cb96f1f..728f45ec3935 100644
--- a/main/SAPI.h
+++ b/main/SAPI.h
@@ -238,9 +238,16 @@ struct _sapi_module_struct {
 	char *name;
 	char *pretty_name;
 
+	/* Must be called by the SAPI once per process, excluding forked processes
+	 */
 	int (*startup)(struct _sapi_module_struct *sapi_module);
 	int (*shutdown)(struct _sapi_module_struct *sapi_module);
 
+	/* Must be called by the SAPI once per request-handling process. The process
+	 * must not fork (without exec) after that. */
+	int (*child_startup)(struct _sapi_module_struct *sapi_module);
+
+	/* Must be called by the SAPI once per request */
 	int (*activate)(void);
 	int (*deactivate)(void);
 
diff --git a/main/main.c b/main/main.c
index 29d8642b8f71..b3f83bfebc1c 100644
--- a/main/main.c
+++ b/main/main.c
@@ -96,6 +96,10 @@ PHPAPI size_t core_globals_offset;
 
 #define SAFE_FILENAME(f) ((f)?(f):"-")
 
+#if ZEND_DEBUG
+static pid_t php_child_started = 0;
+#endif
+
 PHPAPI const char *php_version(void)
 {
 	return PHP_VERSION;
@@ -1736,6 +1740,11 @@ static void sigchld_handler(int apar)
 /* {{{ php_request_startup */
 zend_result php_request_startup(void)
 {
+#if ZEND_DEBUG
+	ZEND_ASSERT(php_child_started == getpid()
+			&& "SAPI must call php_module_child_startup() once per request-handling process");
+#endif
+
 	zend_result retval = SUCCESS;
 
 	zend_interned_strings_activate();
@@ -2358,6 +2367,9 @@ void php_module_shutdown(void)
 	int module_number=0;
 
 	module_shutdown = true;
+#if ZEND_DEBUG
+	php_child_started = 0;
+#endif
 
 	if (!module_initialized) {
 		return;
@@ -2431,6 +2443,21 @@ void php_module_shutdown(void)
 }
 /* }}} */
 
+/* {{{ php_module_child_startup */
+zend_result php_module_child_startup(sapi_module_struct *sf)
+{
+#if ZEND_DEBUG
+	ZEND_ASSERT(php_child_started == 0
+			&& "php_module_child_startup() already called for this process or a parent process");
+	php_child_started = getpid();
+#endif
+
+	zend_child_startup_modules();
+
+	return SUCCESS;
+}
+/* }}} */
+
 PHPAPI bool php_execute_script_ex(zend_file_handle *primary_file, zval *retval)
 {
 	zend_file_handle *prepend_file_p = NULL, *append_file_p = NULL;
diff --git a/main/php.h b/main/php.h
index b10ded010d12..40372ee68963 100644
--- a/main/php.h
+++ b/main/php.h
@@ -382,21 +382,26 @@ END_EXTERN_C()
 #define PHP_ME_MAPPING  ZEND_ME_MAPPING
 #define PHP_FE_END      ZEND_FE_END
 
-#define PHP_MODULE_STARTUP_N	ZEND_MODULE_STARTUP_N
-#define PHP_MODULE_SHUTDOWN_N	ZEND_MODULE_SHUTDOWN_N
-#define PHP_MODULE_ACTIVATE_N	ZEND_MODULE_ACTIVATE_N
-#define PHP_MODULE_DEACTIVATE_N	ZEND_MODULE_DEACTIVATE_N
-#define PHP_MODULE_INFO_N		ZEND_MODULE_INFO_N
-
-#define PHP_MODULE_STARTUP_D	ZEND_MODULE_STARTUP_D
-#define PHP_MODULE_SHUTDOWN_D	ZEND_MODULE_SHUTDOWN_D
-#define PHP_MODULE_ACTIVATE_D	ZEND_MODULE_ACTIVATE_D
-#define PHP_MODULE_DEACTIVATE_D	ZEND_MODULE_DEACTIVATE_D
-#define PHP_MODULE_INFO_D		ZEND_MODULE_INFO_D
+#define PHP_MODULE_STARTUP_N		ZEND_MODULE_STARTUP_N
+#define PHP_MODULE_SHUTDOWN_N		ZEND_MODULE_SHUTDOWN_N
+#define PHP_MODULE_CHILD_STARTUP_N	ZEND_MODULE_CHILD_STARTUP_N
+#define PHP_MODULE_ACTIVATE_N		ZEND_MODULE_ACTIVATE_N
+#define PHP_MODULE_DEACTIVATE_N		ZEND_MODULE_DEACTIVATE_N
+#define PHP_MODULE_INFO_N			ZEND_MODULE_INFO_N
+
+#define PHP_MODULE_STARTUP_D		ZEND_MODULE_STARTUP_D
+#define PHP_MODULE_SHUTDOWN_D		ZEND_MODULE_SHUTDOWN_D
+#define PHP_MODULE_CHILD_STARTUP_D	ZEND_MODULE_CHILD_STARTUP_D
+#define PHP_MODULE_ACTIVATE_D		ZEND_MODULE_ACTIVATE_D
+#define PHP_MODULE_DEACTIVATE_D		ZEND_MODULE_DEACTIVATE_D
+#define PHP_MODULE_INFO_D			ZEND_MODULE_INFO_D
+
+#define PHP_MODULE_SET_CHILD_STARTUP_FUNC ZEND_MODULE_SET_CHILD_STARTUP_FUNC
 
 /* Compatibility macros */
 #define PHP_MINIT		ZEND_MODULE_STARTUP_N
 #define PHP_MSHUTDOWN	ZEND_MODULE_SHUTDOWN_N
+#define PHP_CHINIT		ZEND_MODULE_CHILD_STARTUP_N
 #define PHP_RINIT		ZEND_MODULE_ACTIVATE_N
 #define PHP_RSHUTDOWN	ZEND_MODULE_DEACTIVATE_N
 #define PHP_MINFO		ZEND_MODULE_INFO_N
@@ -405,12 +410,15 @@ END_EXTERN_C()
 
 #define PHP_MINIT_FUNCTION		ZEND_MODULE_STARTUP_D
 #define PHP_MSHUTDOWN_FUNCTION	ZEND_MODULE_SHUTDOWN_D
+#define PHP_CHINIT_FUNCTION		ZEND_MODULE_CHILD_STARTUP_D
 #define PHP_RINIT_FUNCTION		ZEND_MODULE_ACTIVATE_D
 #define PHP_RSHUTDOWN_FUNCTION	ZEND_MODULE_DEACTIVATE_D
 #define PHP_MINFO_FUNCTION		ZEND_MODULE_INFO_D
 #define PHP_GINIT_FUNCTION		ZEND_GINIT_FUNCTION
 #define PHP_GSHUTDOWN_FUNCTION	ZEND_GSHUTDOWN_FUNCTION
 
+#define PHP_MODULE_SET_CHINIT_FUNC PHP_MODULE_SET_CHILD_STARTUP_FUNC
+
 #define PHP_MODULE_GLOBALS		ZEND_MODULE_GLOBALS
 
 
diff --git a/main/php_main.h b/main/php_main.h
index 1fb460f07f26..a8a75c12a689 100644
--- a/main/php_main.h
+++ b/main/php_main.h
@@ -21,6 +21,7 @@
 #include "zend_globals.h"
 #include "php_globals.h"
 #include "SAPI.h"
+#include "zend_modules.h"
 
 BEGIN_EXTERN_C()
 
@@ -40,6 +41,7 @@ PHPAPI zend_result php_request_startup(void);
 PHPAPI void php_request_shutdown(void *dummy);
 PHPAPI zend_result php_module_startup(sapi_module_struct *sf, zend_module_entry *additional_module);
 PHPAPI void php_module_shutdown(void);
+PHPAPI zend_result php_module_child_startup(sapi_module_struct *sf);
 PHPAPI int php_module_shutdown_wrapper(sapi_module_struct *sapi_globals);
 
 PHPAPI zend_result php_register_extensions(zend_module_entry * const * ptr, int count);
diff --git a/sapi/apache2handler/sapi_apache2.c b/sapi/apache2handler/sapi_apache2.c
index a5d4e8984a5a..e0ff3e246251 100644
--- a/sapi/apache2handler/sapi_apache2.c
+++ b/sapi/apache2handler/sapi_apache2.c
@@ -386,6 +386,11 @@ static int php_apache2_startup(sapi_module_struct *sapi_module)
 	return php_module_startup(sapi_module, &php_apache_module);
 }
 
+static int php_apache2_child_startup(sapi_module_struct *sapi_module)
+{
+	return php_module_child_startup(sapi_module);
+}
+
 static sapi_module_struct apache2_sapi_module = {
 	"apache2handler",
 	"Apache 2.0 Handler",
@@ -393,6 +398,8 @@ static sapi_module_struct apache2_sapi_module = {
 	php_apache2_startup,				/* startup */
 	php_module_shutdown_wrapper,			/* shutdown */
 
+	php_apache2_child_startup,			/* child_startup */
+
 	NULL,						/* activate */
 	NULL,						/* deactivate */
 
@@ -755,6 +762,7 @@ zend_first_try {
 static void php_apache_child_init(apr_pool_t *pchild, server_rec *s)
 {
 	apr_pool_cleanup_register(pchild, NULL, php_apache_child_shutdown, apr_pool_cleanup_null);
+	apache2_sapi_module.child_startup(&apache2_sapi_module);
 }
 
 #ifdef ZEND_SIGNALS
diff --git a/sapi/cgi/cgi_main.c b/sapi/cgi/cgi_main.c
index 9d7e66ce2b5b..6475439c7bec 100644
--- a/sapi/cgi/cgi_main.c
+++ b/sapi/cgi/cgi_main.c
@@ -970,6 +970,11 @@ static int php_cgi_startup(sapi_module_struct *sapi_module)
 	return php_module_startup(sapi_module, &cgi_module_entry);
 }
 
+static int php_cgi_child_startup(sapi_module_struct *sapi_module)
+{
+	return php_module_child_startup(sapi_module);
+}
+
 /* {{{ sapi_module_struct cgi_sapi_module */
 static sapi_module_struct cgi_sapi_module = {
 	"cgi-fcgi",						/* name */
@@ -978,6 +983,8 @@ static sapi_module_struct cgi_sapi_module = {
 	php_cgi_startup,				/* startup */
 	php_module_shutdown_wrapper,	/* shutdown */
 
+	php_cgi_child_startup,			/* child_startup */
+
 	sapi_cgi_activate,				/* activate */
 	sapi_cgi_deactivate,			/* deactivate */
 
@@ -1864,7 +1871,8 @@ int main(int argc, char *argv[])
 	}
 
 	/* startup after we get the above ini override se we get things right */
-	if (cgi_sapi_module.startup(&cgi_sapi_module) == FAILURE) {
+	if (cgi_sapi_module.startup(&cgi_sapi_module) == FAILURE
+			|| cgi_sapi_module.child_startup(&cgi_sapi_module) == FAILURE) {
 #ifdef ZTS
 		tsrm_shutdown();
 #endif
diff --git a/sapi/cli/php_cli.c b/sapi/cli/php_cli.c
index e107667828ca..364ffc4dbb32 100644
--- a/sapi/cli/php_cli.c
+++ b/sapi/cli/php_cli.c
@@ -411,6 +411,12 @@ static int php_cli_startup(sapi_module_struct *sapi_module) /* {{{ */
 }
 /* }}} */
 
+static int php_cli_child_startup(sapi_module_struct *sapi_module) /* {{{ */
+{
+	return php_module_child_startup(sapi_module);
+}
+/* }}} */
+
 /* {{{ sapi_cli_ini_defaults */
 
 /* overwritable ini defaults must be set in sapi_cli_ini_defaults() */
@@ -433,6 +439,8 @@ static sapi_module_struct cli_sapi_module = {
 	php_cli_startup,				/* startup */
 	php_module_shutdown_wrapper,	/* shutdown */
 
+	php_cli_child_startup,			/* child_startup */
+
 	NULL,							/* activate */
 	sapi_cli_deactivate,			/* deactivate */
 
@@ -1304,7 +1312,8 @@ int main(int argc, char *argv[])
 	sapi_module->ini_entries = php_ini_builder_finish(&ini_builder);
 
 	/* startup after we get the above ini override se we get things right */
-	if (sapi_module->startup(sapi_module) == FAILURE) {
+	if (sapi_module->startup(sapi_module) == FAILURE
+			|| sapi_module->child_startup(sapi_module) == FAILURE) {
 		/* there is no way to see if we must call zend_ini_deactivate()
 		 * since we cannot check if EG(ini_directives) has been initialized
 		 * because the executor's constructor does not set initialize it.
diff --git a/sapi/cli/php_cli_server.c b/sapi/cli/php_cli_server.c
index e84defb3da46..bf670c217b4a 100644
--- a/sapi/cli/php_cli_server.c
+++ b/sapi/cli/php_cli_server.c
@@ -515,6 +515,11 @@ static int sapi_cli_server_startup(sapi_module_struct *sapi_module) /* {{{ */
 	return php_module_startup(sapi_module, &cli_server_module_entry);
 } /* }}} */
 
+static int sapi_cli_server_child_startup(sapi_module_struct *sapi_module) /* {{{ */
+{
+	return php_module_child_startup(sapi_module);
+} /* }}} */
+
 static size_t sapi_cli_server_ub_write(const char *str, size_t str_length) /* {{{ */
 {
 	php_cli_server_client *client = SG(server_context);
@@ -804,9 +809,11 @@ sapi_module_struct cli_server_sapi_module = {
 	"cli-server",							/* name */
 	"Built-in HTTP server",		/* pretty name */
 
-	sapi_cli_server_startup,				/* startup */
+	sapi_cli_server_startup,		/* startup */
 	php_module_shutdown_wrapper,	/* shutdown */
 
+	sapi_cli_server_child_startup,	/* child_startup */
+
 	NULL,							/* activate */
 	NULL,							/* deactivate */
 
diff --git a/sapi/embed/php_embed.c b/sapi/embed/php_embed.c
index 4626451f9f68..db945e922729 100644
--- a/sapi/embed/php_embed.c
+++ b/sapi/embed/php_embed.c
@@ -122,6 +122,12 @@ static int php_embed_startup(sapi_module_struct *sapi_module)
 	return php_module_startup(sapi_module, NULL);
 }
 
+/* Request-handling process initialization (CHINIT) */
+static int php_embed_child_startup(sapi_module_struct *sapi_module)
+{
+	return php_module_child_startup(sapi_module);
+}
+
 EMBED_SAPI_API sapi_module_struct php_embed_module = {
 	"embed",                       /* name */
 	"PHP Embedded Library",        /* pretty name */
@@ -129,6 +135,8 @@ EMBED_SAPI_API sapi_module_struct php_embed_module = {
 	php_embed_startup,             /* startup */
 	php_module_shutdown_wrapper,   /* shutdown */
 
+	php_embed_child_startup,       /* child_startup */
+
 	NULL,                          /* activate */
 	php_embed_deactivate,          /* deactivate */
 
@@ -224,7 +232,8 @@ EMBED_SAPI_API int php_embed_init(int argc, char **argv)
 	}
 
 	/* Module initialization (MINIT) */
-	if (php_embed_module.startup(&php_embed_module) == FAILURE) {
+	if (php_embed_module.startup(&php_embed_module) == FAILURE
+			|| php_embed_module.child_startup(&php_embed_module) == FAILURE) {
 		return FAILURE;
 	}
 
diff --git a/sapi/fpm/fpm/fpm_children.c b/sapi/fpm/fpm/fpm_children.c
index 285df91a9b69..c90899bcf53d 100644
--- a/sapi/fpm/fpm/fpm_children.c
+++ b/sapi/fpm/fpm/fpm_children.c
@@ -9,6 +9,7 @@
 #include <string.h>
 #include <stdio.h>
 
+#include "SAPI.h"
 #include "fpm.h"
 #include "fpm_children.h"
 #include "fpm_signals.h"
@@ -202,6 +203,8 @@ static void fpm_child_init(struct fpm_worker_pool_s *wp) /* {{{ */
 		zlog(ZLOG_ERROR, "[pool %s] child failed to initialize", wp->config->name);
 		exit(FPM_EXIT_SOFTWARE);
 	}
+
+	sapi_module.child_startup(&sapi_module);
 }
 /* }}} */
 
diff --git a/sapi/fpm/fpm/fpm_main.c b/sapi/fpm/fpm/fpm_main.c
index 9526a04c4187..c99cb062be5c 100644
--- a/sapi/fpm/fpm/fpm_main.c
+++ b/sapi/fpm/fpm/fpm_main.c
@@ -793,6 +793,12 @@ static int php_cgi_startup(sapi_module_struct *sapi_module) /* {{{ */
 }
 /* }}} */
 
+static int php_cgi_child_startup(sapi_module_struct *sapi_module) /* {{{ */
+{
+	return php_module_child_startup(sapi_module);
+}
+/* }}} */
+
 /* {{{ sapi_module_struct cgi_sapi_module */
 static sapi_module_struct cgi_sapi_module = {
 	"fpm-fcgi",						/* name */
@@ -801,6 +807,8 @@ static sapi_module_struct cgi_sapi_module = {
 	php_cgi_startup,				/* startup */
 	php_module_shutdown_wrapper,	/* shutdown */
 
+	php_cgi_child_startup,				/* child_startup */
+
 	sapi_cgi_activate,				/* activate */
 	sapi_cgi_deactivate,			/* deactivate */
 
@@ -1651,6 +1659,7 @@ int main(int argc, char *argv[])
 
 			case 'm': /* list compiled in modules */
 				cgi_sapi_module.startup(&cgi_sapi_module);
+				cgi_sapi_module.child_startup(&cgi_sapi_module);
 				php_output_activate();
 				SG(headers_sent) = 1;
 				php_printf("[PHP Modules]\n");
@@ -1689,6 +1698,7 @@ int main(int argc, char *argv[])
 			case '?':
 			case PHP_GETOPT_INVALID_ARG:
 				cgi_sapi_module.startup(&cgi_sapi_module);
+				cgi_sapi_module.child_startup(&cgi_sapi_module);
 				php_output_activate();
 				SG(headers_sent) = 1;
 				php_cgi_usage(argv[0]);
@@ -1700,6 +1710,7 @@ int main(int argc, char *argv[])
 
 			case 'v': /* show php version & quit */
 				cgi_sapi_module.startup(&cgi_sapi_module);
+				cgi_sapi_module.child_startup(&cgi_sapi_module);
 				if (php_request_startup() == FAILURE) {
 					SG(server_context) = NULL;
 					php_module_shutdown();
@@ -1725,6 +1736,7 @@ int main(int argc, char *argv[])
 	if (php_information) {
 		cgi_sapi_module.phpinfo_as_text = 1;
 		cgi_sapi_module.startup(&cgi_sapi_module);
+		cgi_sapi_module.child_startup(&cgi_sapi_module);
 		if (php_request_startup() == FAILURE) {
 			SG(server_context) = NULL;
 			php_module_shutdown();
@@ -1742,6 +1754,7 @@ int main(int argc, char *argv[])
 	/* No other args are permitted here as there is no interactive mode */
 	if (argc != php_optind) {
 		cgi_sapi_module.startup(&cgi_sapi_module);
+		cgi_sapi_module.child_startup(&cgi_sapi_module);
 		php_output_activate();
 		SG(headers_sent) = 1;
 		php_cgi_usage(argv[0]);
diff --git a/sapi/fuzzer/fuzzer-sapi.c b/sapi/fuzzer/fuzzer-sapi.c
index a018ce23de30..091c417d6035 100644
--- a/sapi/fuzzer/fuzzer-sapi.c
+++ b/sapi/fuzzer/fuzzer-sapi.c
@@ -65,6 +65,11 @@ static int startup(sapi_module_struct *sapi_module)
 	return php_module_startup(sapi_module, NULL);
 }
 
+static int child_startup(sapi_module_struct *sapi_module)
+{
+	return php_module_child_startup(sapi_module);
+}
+
 static size_t ub_write(const char *str, size_t str_length)
 {
 	/* quiet */
@@ -103,6 +108,8 @@ static sapi_module_struct fuzzer_module = {
 	startup,             /* startup */
 	php_module_shutdown_wrapper,   /* shutdown */
 
+	child_startup,                 /* child_startup */
+
 	NULL,                          /* activate */
 	NULL,                          /* deactivate */
 
@@ -159,7 +166,8 @@ int fuzzer_init_php(const char *extra_ini)
 	 */
 	putenv("USE_ZEND_ALLOC=0");
 
-	if (fuzzer_module.startup(&fuzzer_module)==FAILURE) {
+	if (fuzzer_module.startup(&fuzzer_module)==FAILURE
+			|| fuzzer_module.child_startup(&fuzzer_module)) {
 		return FAILURE;
 	}
 
diff --git a/sapi/phpdbg/phpdbg.c b/sapi/phpdbg/phpdbg.c
index a69ac171cfac..962bf914a5b6 100644
--- a/sapi/phpdbg/phpdbg.c
+++ b/sapi/phpdbg/phpdbg.c
@@ -28,6 +28,7 @@
 #include "phpdbg_print.h"
 #include "phpdbg_help.h"
 #include "phpdbg_arginfo.h"
+#include "zend_types.h"
 #include "zend_vm.h"
 #include "php_ini_builder.h"
 
@@ -711,6 +712,11 @@ static inline int php_sapi_phpdbg_module_startup(sapi_module_struct *module) /*
 	return SUCCESS;
 } /* }}} */
 
+static inline int php_sapi_phpdbg_module_child_startup(sapi_module_struct *module) /* {{{ */
+{
+	return php_module_child_startup(module);
+} /* }}} */
+
 static char* php_sapi_phpdbg_read_cookies(void) /* {{{ */
 {
 	return NULL;
@@ -938,6 +944,8 @@ static sapi_module_struct phpdbg_sapi_module = {
 	php_sapi_phpdbg_module_startup, /* startup */
 	php_module_shutdown_wrapper,    /* shutdown */
 
+	php_sapi_phpdbg_module_child_startup, /* child_startup */
+
 	php_sapi_phpdbg_activate,       /* activate */
 	php_sapi_phpdbg_deactivate,     /* deactivate */
 
@@ -1355,7 +1363,8 @@ int main(int argc, char **argv) /* {{{ */
 	/* set flags from command line */
 	PHPDBG_G(flags) = flags;
 
-	if (phpdbg->startup(phpdbg) == SUCCESS) {
+	if (phpdbg->startup(phpdbg) == SUCCESS
+			&& phpdbg->child_startup(phpdbg) == SUCCESS) {
 		zend_mm_heap *mm_heap;
 #ifdef _WIN32
 	EXCEPTION_POINTERS *xp;