diff --git a/src/cmd/link/internal/ld/macho.go b/src/cmd/link/internal/ld/macho.go
index 11cbf81486..d6c28e4790 100644
--- a/src/cmd/link/internal/ld/macho.go
+++ b/src/cmd/link/internal/ld/macho.go
@@ -479,8 +479,11 @@ func (ctxt *Link) domacho() {
 			var version uint32
 			switch ctxt.Arch.Family {
 			case sys.AMD64:
-				// The version must be at least 10.9; see golang.org/issues/30488.
-				version = 10<<16 | 9<<8 | 0<<0 // 10.9.0
+				// This must be fairly recent for Apple signing (go.dev/issue/30488).
+				// Having too old a version here was also implicated in some problems
+				// calling into macOS libraries (go.dev/issue/56784).
+				// In general this can be the most recent supported macOS version.
+				version = 10<<16 | 13<<8 | 0<<0 // 10.13.0
 			case sys.ARM64:
 				version = 11<<16 | 0<<8 | 0<<0 // 11.0.0
 			}
diff --git a/src/runtime/os_darwin.go b/src/runtime/os_darwin.go
index af5c18c301..c4f3bb6a81 100644
--- a/src/runtime/os_darwin.go
+++ b/src/runtime/os_darwin.go
@@ -136,6 +136,8 @@ func osinit() {
 
 	ncpu = getncpu()
 	physPageSize = getPageSize()
+
+	osinit_hack()
 }
 
 func sysctlbynameInt32(name []byte) (int32, int32) {
diff --git a/src/runtime/sys_darwin.go b/src/runtime/sys_darwin.go
index 61b7f8c728..8bff695f57 100644
--- a/src/runtime/sys_darwin.go
+++ b/src/runtime/sys_darwin.go
@@ -179,6 +179,45 @@ func pthread_kill(t pthread, sig uint32) {
 }
 func pthread_kill_trampoline()
 
+// osinit_hack is a clumsy hack to work around Apple libc bugs
+// causing fork+exec to hang in the child process intermittently.
+// See go.dev/issue/33565 and go.dev/issue/56784 for a few reports.
+//
+// The stacks obtained from the hung child processes are in
+// libSystem_atfork_child, which is supposed to reinitialize various
+// parts of the C library in the new process.
+//
+// One common stack dies in _notify_fork_child calling _notify_globals
+// (inlined) calling _os_alloc_once, because _os_alloc_once detects that
+// the once lock is held by the parent process and then calls
+// _os_once_gate_corruption_abort. The allocation is setting up the
+// globals for the notification subsystem. See the source code at [1].
+// To work around this, we can allocate the globals earlier in the Go
+// program's lifetime, before any execs are involved, by calling any
+// notify routine that is exported, calls _notify_globals, and doesn't do
+// anything too expensive otherwise. notify_is_valid_token(0) fits the bill.
+//
+// The other common stack dies in xpc_atfork_child calling
+// _objc_msgSend_uncached which ends up in
+// WAITING_FOR_ANOTHER_THREAD_TO_FINISH_CALLING_+initialize. Of course,
+// whatever thread the child is waiting for is in the parent process and
+// is not going to finish anything in the child process. There is no
+// public source code for these routines, so it is unclear exactly what
+// the problem is. An Apple engineer suggests using xpc_date_create_from_current,
+// which empirically does fix the problem.
+//
+// So osinit_hack_trampoline (in sys_darwin_$GOARCH.s) calls
+// notify_is_valid_token(0) and xpc_date_create_from_current(), which makes the
+// fork+exec hangs stop happening. If Apple fixes the libc bug in
+// some future version of macOS, then we can remove this awful code.
+//
+//go:nosplit
+func osinit_hack() {
+	libcCall(unsafe.Pointer(abi.FuncPCABI0(osinit_hack_trampoline)), nil)
+	return
+}
+func osinit_hack_trampoline()
+
 // mmap is used to do low-level memory allocation via mmap. Don't allow stack
 // splits, since this function (used by sysAlloc) is called in a lot of low-level
 // parts of the runtime and callers often assume it won't acquire any locks.
@@ -548,3 +587,6 @@ func setNonblock(fd int32) {
 //go:cgo_import_dynamic libc_pthread_cond_wait pthread_cond_wait "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_pthread_cond_timedwait_relative_np pthread_cond_timedwait_relative_np "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_pthread_cond_signal pthread_cond_signal "/usr/lib/libSystem.B.dylib"
+
+//go:cgo_import_dynamic libc_notify_is_valid_token notify_is_valid_token "/usr/lib/libSystem.B.dylib"
+//go:cgo_import_dynamic libc_xpc_date_create_from_current xpc_date_create_from_current "/usr/lib/libSystem.B.dylib"
diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s
index 369b12e8f9..6eaeeb915f 100644
--- a/src/runtime/sys_darwin_amd64.s
+++ b/src/runtime/sys_darwin_amd64.s
@@ -597,6 +597,15 @@ TEXT runtime·pthread_kill_trampoline(SB),NOSPLIT,$0
 	POPQ	BP
 	RET
 
+TEXT runtime·osinit_hack_trampoline(SB),NOSPLIT,$0
+	PUSHQ	BP
+	MOVQ	SP, BP
+	MOVQ	$0, DI	// arg 1 val
+	CALL	libc_notify_is_valid_token(SB)
+	CALL	libc_xpc_date_create_from_current(SB)
+	POPQ	BP
+	RET
+
 // syscall calls a function in libc on behalf of the syscall package.
 // syscall takes a pointer to a struct like:
 // struct {
diff --git a/src/runtime/sys_darwin_arm64.s b/src/runtime/sys_darwin_arm64.s
index 4fa99cc0f9..4a51fb3a86 100644
--- a/src/runtime/sys_darwin_arm64.s
+++ b/src/runtime/sys_darwin_arm64.s
@@ -458,6 +458,12 @@ TEXT runtime·pthread_setspecific_trampoline(SB),NOSPLIT,$0
 	BL	libc_pthread_setspecific(SB)
 	RET
 
+TEXT runtime·osinit_hack_trampoline(SB),NOSPLIT,$0
+	MOVD	$0, R0	// arg 1 val
+	BL	libc_notify_is_valid_token(SB)
+	BL	libc_xpc_date_create_from_current(SB)
+	RET
+
 // syscall calls a function in libc on behalf of the syscall package.
 // syscall takes a pointer to a struct like:
 // struct {