diff --git a/src/oom/oomctl.c b/src/oom/oomctl.c
index 09df6080a8..d9098de0eb 100644
--- a/src/oom/oomctl.c
+++ b/src/oom/oomctl.c
@@ -1,7 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
 #include <getopt.h>
-#include <unistd.h>
+
+#include "sd-bus.h"
 
 #include "alloc-util.h"
 #include "build.h"
@@ -12,7 +13,6 @@
 #include "main-func.h"
 #include "pager.h"
 #include "pretty-print.h"
-#include "terminal-util.h"
 #include "verbs.h"
 
 static PagerFlags arg_pager_flags = 0;
diff --git a/src/oom/oomd-conf.c b/src/oom/oomd-conf.c
index 1fcac36251..299d2afe96 100644
--- a/src/oom/oomd-conf.c
+++ b/src/oom/oomd-conf.c
@@ -4,6 +4,9 @@
 #include "log.h"
 #include "oomd-conf.h"
 #include "oomd-manager.h"
+#include "parse-util.h"
+#include "string-util.h"
+#include "time-util.h"
 
 static int config_parse_duration(
                 const char *unit,
diff --git a/src/oom/oomd-conf.h b/src/oom/oomd-conf.h
index 0283b9e61d..429b976b91 100644
--- a/src/oom/oomd-conf.h
+++ b/src/oom/oomd-conf.h
@@ -1,8 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include "conf-parser.h"
-#include "oomd-manager.h"
+typedef struct Manager Manager;
 
 void manager_set_defaults(Manager *m);
 
diff --git a/src/oom/oomd-manager-bus.c b/src/oom/oomd-manager-bus.c
index f2bf6b41cb..08f261fcc1 100644
--- a/src/oom/oomd-manager-bus.c
+++ b/src/oom/oomd-manager-bus.c
@@ -1,15 +1,13 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-#include <linux/capability.h>
+#include "sd-bus.h"
 
 #include "alloc-util.h"
-#include "bus-common-errors.h"
-#include "bus-polkit.h"
+#include "bus-object.h"
 #include "fd-util.h"
 #include "memfd-util.h"
 #include "oomd-manager.h"
 #include "oomd-manager-bus.h"
-#include "user-util.h"
 
 static int bus_method_dump_by_fd(sd_bus_message *message, void *userdata, sd_bus_error *error) {
         _cleanup_free_ char *dump = NULL;
diff --git a/src/oom/oomd-manager-bus.h b/src/oom/oomd-manager-bus.h
index 7935b357a4..70c473f15b 100644
--- a/src/oom/oomd-manager-bus.h
+++ b/src/oom/oomd-manager-bus.h
@@ -1,8 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include "bus-object.h"
-
-typedef struct Manager Manager;
+#include "forward.h"
 
 extern const BusObjectImplementation manager_object;
diff --git a/src/oom/oomd-manager.c b/src/oom/oomd-manager.c
index b494ea0c28..2cdd404bf0 100644
--- a/src/oom/oomd-manager.c
+++ b/src/oom/oomd-manager.c
@@ -1,25 +1,30 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+#include "sd-bus.h"
 #include "sd-daemon.h"
+#include "sd-event.h"
 #include "sd-json.h"
 
 #include "alloc-util.h"
 #include "bus-log-control-api.h"
-#include "bus-polkit.h"
+#include "bus-object.h"
 #include "bus-util.h"
 #include "cgroup-util.h"
+#include "constants.h"
 #include "daemon-util.h"
 #include "fd-util.h"
-#include "fileio.h"
 #include "format-util.h"
 #include "json-util.h"
-#include "memory-util.h"
 #include "memstream-util.h"
 #include "oomd-conf.h"
 #include "oomd-manager.h"
 #include "oomd-manager-bus.h"
+#include "parse-util.h"
 #include "path-util.h"
 #include "percent-util.h"
+#include "set.h"
+#include "string-util.h"
+#include "time-util.h"
 #include "varlink-io.systemd.oom.h"
 #include "varlink-io.systemd.service.h"
 #include "varlink-util.h"
diff --git a/src/oom/oomd-manager.h b/src/oom/oomd-manager.h
index a40946ce4e..311250c6f3 100644
--- a/src/oom/oomd-manager.h
+++ b/src/oom/oomd-manager.h
@@ -1,11 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include "sd-bus.h"
-#include "sd-event.h"
-#include "sd-varlink.h"
-
-#include "conf-parser.h"
+#include "conf-parser-forward.h"
+#include "forward.h"
 #include "oomd-util.h"
 
 /* Polling interval for monitoring stats */
@@ -27,9 +24,7 @@
 #define RECLAIM_DURATION_USEC (30 * USEC_PER_SEC)
 #define POST_ACTION_DELAY_USEC (15 * USEC_PER_SEC)
 
-typedef struct Manager Manager;
-
-struct Manager {
+typedef struct Manager {
         sd_bus *bus;
         sd_event *event;
 
@@ -59,7 +54,7 @@ struct Manager {
         /* This varlink server object is used to manage systemd-oomd's varlink server which is used by user
          * managers to report changes in ManagedOOM settings (oomd server - systemd client). */
         sd_varlink_server *varlink_server;
-};
+} Manager;
 
 Manager* manager_free(Manager *m);
 DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free);
diff --git a/src/oom/oomd-util.c b/src/oom/oomd-util.c
index b6b6c2a2f1..de0f2e6854 100644
--- a/src/oom/oomd-util.c
+++ b/src/oom/oomd-util.c
@@ -1,8 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-#include <sys/xattr.h>
-#include <unistd.h>
-
+#include "alloc-util.h"
 #include "errno-util.h"
 #include "fd-util.h"
 #include "fileio.h"
@@ -12,12 +10,14 @@
 #include "oomd-util.h"
 #include "parse-util.h"
 #include "path-util.h"
+#include "pidref.h"
 #include "procfs-util.h"
+#include "set.h"
 #include "signal-util.h"
 #include "sort-util.h"
-#include "stat-util.h"
 #include "stdio-util.h"
-#include "user-util.h"
+#include "string-util.h"
+#include "time-util.h"
 
 DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
                 oomd_cgroup_ctx_hash_ops,
diff --git a/src/oom/oomd-util.h b/src/oom/oomd-util.h
index 14fe5c5eba..cfb310ff32 100644
--- a/src/oom/oomd-util.h
+++ b/src/oom/oomd-util.h
@@ -1,10 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include <stdbool.h>
-
 #include "cgroup-util.h"
-#include "hashmap.h"
+#include "forward.h"
 #include "psi-util.h"
 
 #define DUMP_ON_KILL_COUNT 10u
diff --git a/src/oom/oomd.c b/src/oom/oomd.c
index d0876d789f..b1d3efb8f5 100644
--- a/src/oom/oomd.c
+++ b/src/oom/oomd.c
@@ -2,12 +2,13 @@
 
 #include <getopt.h>
 
+#include "sd-event.h"
+
 #include "alloc-util.h"
 #include "build.h"
 #include "bus-log-control-api.h"
 #include "bus-object.h"
 #include "cgroup-util.h"
-#include "conf-parser.h"
 #include "daemon-util.h"
 #include "fileio.h"
 #include "log.h"
@@ -18,7 +19,6 @@
 #include "parse-util.h"
 #include "pretty-print.h"
 #include "psi-util.h"
-#include "signal-util.h"
 
 static bool arg_dry_run = false;
 
diff --git a/src/oom/test-oomd-util.c b/src/oom/test-oomd-util.c
index 2eca39c295..3c5159129f 100644
--- a/src/oom/test-oomd-util.c
+++ b/src/oom/test-oomd-util.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+#include <stdlib.h>
 #include <unistd.h>
 
 #include "alloc-util.h"
@@ -7,13 +8,12 @@
 #include "cgroup-util.h"
 #include "fd-util.h"
 #include "fileio.h"
-#include "fs-util.h"
 #include "oomd-util.h"
 #include "parse-util.h"
 #include "path-util.h"
-#include "string-util.h"
-#include "strv.h"
+#include "set.h"
 #include "tests.h"
+#include "time-util.h"
 #include "tmpfile-util.h"
 
 static int fork_and_sleep(unsigned sleep_min) {