diff --git a/cnf/make.globals b/cnf/make.globals
index af2642988a..2bb7a65593 100644
--- a/cnf/make.globals
+++ b/cnf/make.globals
@@ -1,4 +1,4 @@
-# Copyright 1999-2020 Gentoo Authors
+# Copyright 1999-2024 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 # System-wide defaults for the Portage system
 
@@ -77,7 +77,7 @@ FETCHCOMMAND_SFTP="bash -c \"x=\\\${2#sftp://} ; host=\\\${x%%/*} ; port=\\\${ho
 FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs
           binpkg-multi-instance buildpkg-live
           config-protect-if-modified distlocks ebuild-locks
-          fixlafiles ipc-sandbox merge-sync multilib-strict
+          fixlafiles ipc-sandbox merge-sync merge-wait multilib-strict
           network-sandbox news parallel-fetch pkgdir-index-trusted pid-sandbox
           preserve-libs protect-owned qa-unresolved-soname-deps
           sandbox sfperms strict
diff --git a/lib/_emerge/Scheduler.py b/lib/_emerge/Scheduler.py
index ae01214d32..9950792dc9 100644
--- a/lib/_emerge/Scheduler.py
+++ b/lib/_emerge/Scheduler.py
@@ -1521,14 +1521,16 @@ def _build_exit(self, build):
             self.curval += 1
             merge = PackageMerge(merge=build, scheduler=self._sched_iface)
             self._running_tasks[id(merge)] = merge
-            if (
-                not build.build_opts.buildpkgonly
-                and build.pkg in self._deep_system_deps
+            # By default, merge-wait only allows merge when no builds are executing.
+            # As a special exception, dependencies on system packages are frequently
+            # unspecified and will therefore force merge-wait.
+            is_system_pkg = build.pkg in self._deep_system_deps
+            if not build.build_opts.buildpkgonly and (
+                "merge-wait" in build.settings.features or is_system_pkg
             ):
-                # Since dependencies on system packages are frequently
-                # unspecified, merge them only when no builds are executing.
                 self._merge_wait_queue.append(merge)
-                merge.addStartListener(self._system_merge_started)
+                if is_system_pkg:
+                    merge.addStartListener(self._system_merge_started)
             else:
                 self._task_queues.merge.add(merge)
                 merge.addExitListener(self._merge_exit)
diff --git a/lib/portage/const.py b/lib/portage/const.py
index bf310bb6e0..1f468a1abf 100644
--- a/lib/portage/const.py
+++ b/lib/portage/const.py
@@ -1,5 +1,5 @@
 # portage: Constants
-# Copyright 1998-2023 Gentoo Authors
+# Copyright 1998-2024 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 import os
@@ -194,6 +194,7 @@
         "keepwork",
         "lmirror",
         "merge-sync",
+        "merge-wait",
         "metadata-transfer",
         "mirror",
         "mount-sandbox",
diff --git a/man/make.conf.5 b/man/make.conf.5
index f527166da3..20dc9cb52d 100644
--- a/man/make.conf.5
+++ b/man/make.conf.5
@@ -1,4 +1,4 @@
-.TH "MAKE.CONF" "5" "Mar 2023" "Portage @VERSION@" "Portage"
+.TH "MAKE.CONF" "5" "Jan 2024" "Portage @VERSION@" "Portage"
 .SH "NAME"
 make.conf \- custom settings for Portage
 .SH "SYNOPSIS"
@@ -565,6 +565,15 @@ After a package is merged or unmerged, sync relevant files to
 disk in order to avoid data\-loss in the event of a power failure.
 This feature is enabled by default.
 .TP
+.B merge\-wait
+Wait for all builds to complete before merging new packages, which only
+matters when using the \fBemerge\fR(1) \fB\-\-jobs\fR option. This
+feature is always effectively enabled and it cannot be disabled for
+packages that satisfy direct or indirect dependencies of the system
+set. For other packages, it can be disabled in order to trade the
+possibility of random build failures for greater parallelism.
+This feature is enabled by default.
+.TP
 .B metadata\-transfer
 Automatically perform a metadata transfer when `emerge \-\-sync` is run.
 In versions of portage >=2.1.5, this feature is disabled by
@@ -637,8 +646,9 @@ terminal to view parallel-fetch progress.
 .TP
 .B parallel\-install
 Use finer\-grained locks when installing packages, allowing for greater
-parallelization. For additional parallelization, disable
-\fIebuild\-locks\fR.
+parallelism. Note that \fIparallel\-install\fR currently has no effect
+unless \fImerge\-wait\fR is disabled. For additional parallelism,
+disable \fIebuild\-locks\fR.
 .TP
 .B pid\-sandbox
 Isolate the process space for the ebuild processes. This makes it