diff --git a/ext/opcache/ZendAccelerator.c b/ext/opcache/ZendAccelerator.c
index 9ef74973a4df..e6a2b90e8fff 100644
--- a/ext/opcache/ZendAccelerator.c
+++ b/ext/opcache/ZendAccelerator.c
@@ -4524,16 +4524,6 @@ static void preload_load(size_t orig_map_ptr_static_last)
 		}
 	}
 
-	if (EG(zend_constants)) {
-		EG(persistent_constants_count) = EG(zend_constants)->nNumUsed;
-	}
-	if (EG(function_table)) {
-		EG(persistent_functions_count) = EG(function_table)->nNumUsed;
-	}
-	if (EG(class_table)) {
-		EG(persistent_classes_count)   = EG(class_table)->nNumUsed;
-	}
-
 	size_t old_map_ptr_last = CG(map_ptr_last);
 	if (zend_map_ptr_static_last != ZCSG(map_ptr_static_last) || old_map_ptr_last != ZCSG(map_ptr_last)) {
 		CG(map_ptr_last) = ZCSG(map_ptr_last);
@@ -4803,6 +4793,12 @@ static zend_result accel_preload(const char *config, bool in_child)
 
 		preload_load(orig_map_ptr_static_last);
 
+		/* Update persistent counts, as shutdown will discard anything past
+		 * that, and these tables are aliases to global ones at this point. */
+		EG(persistent_functions_count) = EG(function_table)->nNumUsed;
+		EG(persistent_classes_count)   = EG(class_table)->nNumUsed;
+		EG(persistent_constants_count) = EG(zend_constants)->nNumUsed;
+
 		/* Store individual scripts with unlinked classes */
 		HANDLE_BLOCK_INTERRUPTIONS();
 		SHM_UNPROTECT();
@@ -5094,13 +5090,45 @@ static zend_result accel_finish_startup(void)
 
 		exit(ret == SUCCESS ? 0 : 1);
 	} else { /* parent */
-		int status;
+# ifdef HAVE_SIGPROCMASK
+		/* Interrupting the waitpid() call below with a signal would cause the
+		 * process to exit. This is fine when the signal disposition is set to
+		 * terminate the process, but not otherwise.
+		 * When running the apache2handler, preloading is performed in the
+		 * control process. SIGUSR1 and SIGHUP are used to tell the control
+		 * process to restart children. Exiting when these signals are received
+		 * would unexpectedly shutdown the server instead of restarting it.
+		 * Block the USR1 and HUP signals from being delivered during the
+		 * syscall when running the apache2handler SAPI, as these are not
+		 * supposed to terminate the process. See GH-20051. */
+		bool is_apache2handler = strcmp(sapi_module.name, "apache2handler") == 0;
+		sigset_t set, oldset;
+		if (is_apache2handler) {
+			if (sigemptyset(&set)
+					|| sigaddset(&set, SIGUSR1)
+					|| sigaddset(&set, SIGHUP)) {
+				ZEND_UNREACHABLE();
+			}
+			if (sigprocmask(SIG_BLOCK, &set, &oldset)) {
+				ZEND_UNREACHABLE();
+			}
+		}
+# endif
 
+		int status;
 		if (waitpid(pid, &status, 0) < 0) {
 			zend_shared_alloc_unlock();
 			zend_accel_error_noreturn(ACCEL_LOG_FATAL, "Preloading failed to waitpid(%d)", pid);
 		}
 
+# ifdef HAVE_SIGPROCMASK
+		if (is_apache2handler) {
+			if (sigprocmask(SIG_SETMASK, &oldset, NULL)) {
+				ZEND_UNREACHABLE();
+			}
+		}
+# endif
+
 		if (ZCSG(preload_script)) {
 			preload_load(zend_map_ptr_static_last);
 		}