diff --git a/src/basic/af-list.h b/src/basic/af-list.h
index 65656022cc..1684bc6a0f 100644
--- a/src/basic/af-list.h
+++ b/src/basic/af-list.h
@@ -20,6 +20,8 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <sys/socket.h>
+
 #include "string-util.h"
 
 const char *af_to_name(int id);
diff --git a/src/basic/calendarspec.c b/src/basic/calendarspec.c
index d1ba1681fb..fd78022773 100644
--- a/src/basic/calendarspec.c
+++ b/src/basic/calendarspec.c
@@ -35,6 +35,7 @@
 #include "fileio.h"
 #include "macro.h"
 #include "parse-util.h"
+#include "process-util.h"
 #include "string-util.h"
 #include "time-util.h"
 
diff --git a/src/basic/errno-list.c b/src/basic/errno-list.c
index d8eedfc0ad..7eb28b8fd1 100644
--- a/src/basic/errno-list.c
+++ b/src/basic/errno-list.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <string.h>
 
 #include "errno-list.h"
diff --git a/src/basic/ether-addr-util.c b/src/basic/ether-addr-util.c
index bbe8bf0006..bfbd1a4931 100644
--- a/src/basic/ether-addr-util.c
+++ b/src/basic/ether-addr-util.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <net/ethernet.h>
 #include <stdio.h>
 #include <sys/types.h>
diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index 16f97893c9..57d22b8abb 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -39,6 +39,7 @@
 #include "mkdir.h"
 #include "parse-util.h"
 #include "path-util.h"
+#include "process-util.h"
 #include "stat-util.h"
 #include "stdio-util.h"
 #include "string-util.h"
diff --git a/src/basic/gunicode.c b/src/basic/gunicode.c
index e6ac0545a4..8aff4a0fc5 100644
--- a/src/basic/gunicode.c
+++ b/src/basic/gunicode.c
@@ -4,8 +4,6 @@
  *  Copyright 2000, 2005 Red Hat, Inc.
  */
 
-#include <stdlib.h>
-
 #include "gunicode.h"
 
 #define unichar uint32_t
diff --git a/src/basic/hash-funcs.c b/src/basic/hash-funcs.c
index e69f81558d..5267758769 100644
--- a/src/basic/hash-funcs.c
+++ b/src/basic/hash-funcs.c
@@ -19,6 +19,8 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <string.h>
+
 #include "hash-funcs.h"
 
 void string_hash_func(const void *p, struct siphash *state) {
diff --git a/src/basic/hostname-util.h b/src/basic/hostname-util.h
index d837d6f28c..edae52e3db 100644
--- a/src/basic/hostname-util.h
+++ b/src/basic/hostname-util.h
@@ -21,6 +21,7 @@
 ***/
 
 #include <stdbool.h>
+#include <stdio.h>
 
 #include "macro.h"
 
diff --git a/src/basic/journal-importer.c b/src/basic/journal-importer.c
index 6942c370cb..11054589e3 100644
--- a/src/basic/journal-importer.c
+++ b/src/basic/journal-importer.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <unistd.h>
 
 #include "alloc-util.h"
diff --git a/src/basic/log.c b/src/basic/log.c
index 20d9588e2f..b1b4486627 100644
--- a/src/basic/log.c
+++ b/src/basic/log.c
@@ -1239,7 +1239,6 @@ void log_received_signal(int level, const struct signalfd_siginfo *si) {
                 log_full(level,
                          "Received SIG%s.",
                          signal_to_string(si->ssi_signo));
-
 }
 
 int log_syntax_internal(
@@ -1300,3 +1299,10 @@ void log_set_always_reopen_console(bool b) {
 void log_set_open_when_needed(bool b) {
         open_when_needed = b;
 }
+
+int log_emergency_level(void) {
+        /* Returns the log level to use for log_emergency() logging. We use LOG_EMERG only when we are PID 1, as only
+         * then the system of the whole system is obviously affected. */
+
+        return getpid_cached() == 1 ? LOG_EMERG : LOG_ERR;
+}
diff --git a/src/basic/log.h b/src/basic/log.h
index 28300312f6..a731c75153 100644
--- a/src/basic/log.h
+++ b/src/basic/log.h
@@ -20,18 +20,16 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <errno.h>
 #include <stdarg.h>
 #include <stdbool.h>
 #include <stdlib.h>
-#include <sys/signalfd.h>
-#include <sys/socket.h>
 #include <syslog.h>
 
-#include "sd-id128.h"
-
 #include "macro.h"
-#include "process-util.h"
+
+/* Some structures we reference but don't want to pull in headers for */
+struct iovec;
+struct signalfd_siginfo;
 
 typedef enum LogRealm {
         LOG_REALM_SYSTEMD,
@@ -194,7 +192,7 @@ int log_struct_iovec_internal(
                 const char *file,
                 int line,
                 const char *func,
-                const struct iovec input_iovec[],
+                const struct iovec *input_iovec,
                 size_t n_input_iovec);
 
 /* This modifies the buffer passed! */
@@ -252,13 +250,15 @@ void log_assert_failed_return_realm(
 
 #define log_full(level, ...) log_full_errno((level), 0, __VA_ARGS__)
 
+int log_emergency_level(void);
+
 /* Normal logging */
 #define log_debug(...)     log_full(LOG_DEBUG,   __VA_ARGS__)
 #define log_info(...)      log_full(LOG_INFO,    __VA_ARGS__)
 #define log_notice(...)    log_full(LOG_NOTICE,  __VA_ARGS__)
 #define log_warning(...)   log_full(LOG_WARNING, __VA_ARGS__)
 #define log_error(...)     log_full(LOG_ERR,     __VA_ARGS__)
-#define log_emergency(...) log_full(getpid_cached() == 1 ? LOG_EMERG : LOG_ERR, __VA_ARGS__)
+#define log_emergency(...) log_full(log_emergency_level(), __VA_ARGS__)
 
 /* Logging triggered by an errno-like error */
 #define log_debug_errno(error, ...)     log_full_errno(LOG_DEBUG,   error, __VA_ARGS__)
@@ -266,7 +266,7 @@ void log_assert_failed_return_realm(
 #define log_notice_errno(error, ...)    log_full_errno(LOG_NOTICE,  error, __VA_ARGS__)
 #define log_warning_errno(error, ...)   log_full_errno(LOG_WARNING, error, __VA_ARGS__)
 #define log_error_errno(error, ...)     log_full_errno(LOG_ERR,     error, __VA_ARGS__)
-#define log_emergency_errno(error, ...) log_full_errno(getpid_cached() == 1 ? LOG_EMERG : LOG_ERR, error, __VA_ARGS__)
+#define log_emergency_errno(error, ...) log_full_errno(log_emergency_level(), error, __VA_ARGS__)
 
 #ifdef LOG_TRACE
 #  define log_trace(...) log_debug(__VA_ARGS__)
diff --git a/src/basic/process-util.h b/src/basic/process-util.h
index fdb1790b2e..267888a625 100644
--- a/src/basic/process-util.h
+++ b/src/basic/process-util.h
@@ -21,6 +21,7 @@
 ***/
 
 #include <alloca.h>
+#include <errno.h>
 #include <sched.h>
 #include <signal.h>
 #include <stdbool.h>
diff --git a/src/basic/random-util.c b/src/basic/random-util.c
index 1bc8000896..7457815fa2 100644
--- a/src/basic/random-util.c
+++ b/src/basic/random-util.c
@@ -21,11 +21,12 @@
 #include <elf.h>
 #include <errno.h>
 #include <fcntl.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <sys/time.h>
 #include <linux/random.h>
+#include <stdbool.h>
 #include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
 
 #if HAVE_SYS_AUXV_H
 #  include <sys/auxv.h>
diff --git a/src/basic/securebits-util.c b/src/basic/securebits-util.c
index b5f6418a6c..441d386f9e 100644
--- a/src/basic/securebits-util.c
+++ b/src/basic/securebits-util.c
@@ -19,6 +19,7 @@
 ***/
 
 #include <errno.h>
+#include <stdio.h>
 
 #include "alloc-util.h"
 #include "extract-word.h"
diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index d6371f833d..2c70cade14 100644
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -41,6 +41,7 @@
 #include "missing.h"
 #include "parse-util.h"
 #include "path-util.h"
+#include "process-util.h"
 #include "socket-util.h"
 #include "string-table.h"
 #include "string-util.h"
diff --git a/src/basic/stat-util.c b/src/basic/stat-util.c
index 96fc8b3787..3a54103f1b 100644
--- a/src/basic/stat-util.c
+++ b/src/basic/stat-util.c
@@ -21,10 +21,11 @@
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
-#include <sys/stat.h>
-#include <sys/types.h>
 #include <linux/magic.h>
+#include <sched.h>
+#include <sys/stat.h>
 #include <sys/statvfs.h>
+#include <sys/types.h>
 #include <unistd.h>
 
 #include "dirent-util.h"
diff --git a/src/basic/time-util.c b/src/basic/time-util.c
index cbb5285018..4a341e208f 100644
--- a/src/basic/time-util.c
+++ b/src/basic/time-util.c
@@ -38,6 +38,7 @@
 #include "macro.h"
 #include "parse-util.h"
 #include "path-util.h"
+#include "process-util.h"
 #include "string-util.h"
 #include "strv.h"
 #include "time-util.h"
diff --git a/src/basic/verbs.c b/src/basic/verbs.c
index 556acdcaa3..47644670da 100644
--- a/src/basic/verbs.c
+++ b/src/basic/verbs.c
@@ -22,10 +22,12 @@
 #include <getopt.h>
 #include <stdbool.h>
 #include <stddef.h>
+#include <string.h>
 
 #include "env-util.h"
 #include "log.h"
 #include "macro.h"
+#include "process-util.h"
 #include "string-util.h"
 #include "verbs.h"
 #include "virt.h"
diff --git a/src/boot/bootctl.c b/src/boot/bootctl.c
index 48fdf97c7f..1cc77e29f9 100644
--- a/src/boot/bootctl.c
+++ b/src/boot/bootctl.c
@@ -36,6 +36,8 @@
 #include <sys/statfs.h>
 #include <unistd.h>
 
+#include "sd-id128.h"
+
 #include "alloc-util.h"
 #include "blkid-util.h"
 #include "bootspec.h"
diff --git a/src/core/dbus.c b/src/core/dbus.c
index 5e8a299983..258f4c6379 100644
--- a/src/core/dbus.c
+++ b/src/core/dbus.c
@@ -41,6 +41,7 @@
 #include "log.h"
 #include "missing.h"
 #include "mkdir.h"
+#include "process-util.h"
 #include "selinux-access.h"
 #include "special.h"
 #include "string-util.h"
diff --git a/src/core/locale-setup.c b/src/core/locale-setup.c
index 6240a83197..0c43cf2418 100644
--- a/src/core/locale-setup.c
+++ b/src/core/locale-setup.c
@@ -20,6 +20,7 @@
 
 #include <errno.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "env-util.h"
 #include "fileio.h"
diff --git a/src/core/umount.c b/src/core/umount.c
index 6b0100fb44..731436af27 100644
--- a/src/core/umount.c
+++ b/src/core/umount.c
@@ -38,6 +38,7 @@
 #include "mount-setup.h"
 #include "mount-util.h"
 #include "path-util.h"
+#include "process-util.h"
 #include "signal-util.h"
 #include "string-util.h"
 #include "udev-util.h"
diff --git a/src/firstboot/firstboot.c b/src/firstboot/firstboot.c
index 207ddeb70f..1dbceb8803 100644
--- a/src/firstboot/firstboot.c
+++ b/src/firstboot/firstboot.c
@@ -23,6 +23,8 @@
 #include <shadow.h>
 #include <unistd.h>
 
+#include "sd-id128.h"
+
 #include "alloc-util.h"
 #include "ask-password-api.h"
 #include "copy.h"
diff --git a/src/import/export.c b/src/import/export.c
index 753d1399f5..0f32b90051 100644
--- a/src/import/export.c
+++ b/src/import/export.c
@@ -21,6 +21,7 @@
 #include <getopt.h>
 
 #include "sd-event.h"
+#include "sd-id128.h"
 
 #include "alloc-util.h"
 #include "export-raw.h"
diff --git a/src/import/import-common.c b/src/import/import-common.c
index aa7ab974d2..c24a0b0c86 100644
--- a/src/import/import-common.c
+++ b/src/import/import-common.c
@@ -27,6 +27,7 @@
 #include "capability-util.h"
 #include "fd-util.h"
 #include "import-common.h"
+#include "process-util.h"
 #include "signal-util.h"
 #include "util.h"
 
diff --git a/src/import/import.c b/src/import/import.c
index cc454ee15b..454e64e3cb 100644
--- a/src/import/import.c
+++ b/src/import/import.c
@@ -21,6 +21,7 @@
 #include <getopt.h>
 
 #include "sd-event.h"
+#include "sd-id128.h"
 
 #include "alloc-util.h"
 #include "fd-util.h"
diff --git a/src/import/pull.c b/src/import/pull.c
index 46e0fd5acb..325f7e3d50 100644
--- a/src/import/pull.c
+++ b/src/import/pull.c
@@ -21,6 +21,7 @@
 #include <getopt.h>
 
 #include "sd-event.h"
+#include "sd-id128.h"
 
 #include "alloc-util.h"
 #include "hostname-util.h"
diff --git a/src/initctl/initctl.c b/src/initctl/initctl.c
index 5488999727..c1af13d15b 100644
--- a/src/initctl/initctl.c
+++ b/src/initctl/initctl.c
@@ -38,6 +38,7 @@
 #include "log.h"
 #include "special.h"
 #include "util.h"
+#include "process-util.h"
 
 #define SERVER_FD_MAX 16
 #define TIMEOUT_MSEC ((int) (DEFAULT_EXIT_USEC/USEC_PER_MSEC))
diff --git a/src/journal-remote/journal-remote.c b/src/journal-remote/journal-remote.c
index a8755751ee..66d5369a54 100644
--- a/src/journal-remote/journal-remote.c
+++ b/src/journal-remote/journal-remote.c
@@ -43,6 +43,7 @@
 #include "journald-native.h"
 #include "macro.h"
 #include "parse-util.h"
+#include "process-util.h"
 #include "signal-util.h"
 #include "socket-util.h"
 #include "stat-util.h"
diff --git a/src/journal-remote/journal-upload.c b/src/journal-remote/journal-upload.c
index 7566543c1a..0b74ca98a7 100644
--- a/src/journal-remote/journal-upload.c
+++ b/src/journal-remote/journal-upload.c
@@ -37,6 +37,7 @@
 #include "log.h"
 #include "mkdir.h"
 #include "parse-util.h"
+#include "process-util.h"
 #include "sigbus.h"
 #include "signal-util.h"
 #include "string-util.h"
diff --git a/src/journal/journald.c b/src/journal/journald.c
index 6d670e2f4f..2724a2df95 100644
--- a/src/journal/journald.c
+++ b/src/journal/journald.c
@@ -28,6 +28,7 @@
 #include "journald-kmsg.h"
 #include "journald-server.h"
 #include "journald-syslog.h"
+#include "process-util.h"
 #include "sigbus.h"
 
 int main(int argc, char *argv[]) {
diff --git a/src/journal/sd-journal.c b/src/journal/sd-journal.c
index 8a1b161d8f..6da7bf8e81 100644
--- a/src/journal/sd-journal.c
+++ b/src/journal/sd-journal.c
@@ -48,6 +48,7 @@
 #include "lookup3.h"
 #include "missing.h"
 #include "path-util.h"
+#include "process-util.h"
 #include "replace-var.h"
 #include "stat-util.h"
 #include "stdio-util.h"
diff --git a/src/journal/test-compress-benchmark.c b/src/journal/test-compress-benchmark.c
index 409a876054..1f77197549 100644
--- a/src/journal/test-compress-benchmark.c
+++ b/src/journal/test-compress-benchmark.c
@@ -23,6 +23,7 @@
 #include "env-util.h"
 #include "macro.h"
 #include "parse-util.h"
+#include "process-util.h"
 #include "random-util.h"
 #include "string-util.h"
 #include "util.h"
diff --git a/src/libsystemd-network/network-internal.c b/src/libsystemd-network/network-internal.c
index c20e9fca35..94386e4860 100644
--- a/src/libsystemd-network/network-internal.c
+++ b/src/libsystemd-network/network-internal.c
@@ -22,6 +22,7 @@
 #include <linux/if.h>
 #include <netinet/ether.h>
 
+#include "sd-id128.h"
 #include "sd-ndisc.h"
 
 #include "alloc-util.h"
diff --git a/src/libsystemd-network/sd-dhcp-server.c b/src/libsystemd-network/sd-dhcp-server.c
index 63fb355e85..907b72391b 100644
--- a/src/libsystemd-network/sd-dhcp-server.c
+++ b/src/libsystemd-network/sd-dhcp-server.c
@@ -28,6 +28,7 @@
 #include "dhcp-server-internal.h"
 #include "fd-util.h"
 #include "in-addr-util.h"
+#include "sd-id128.h"
 #include "siphash24.h"
 #include "string-util.h"
 #include "unaligned.h"
diff --git a/src/libsystemd-network/sd-ipv4ll.c b/src/libsystemd-network/sd-ipv4ll.c
index 23e2f5211d..f3d09eb30a 100644
--- a/src/libsystemd-network/sd-ipv4ll.c
+++ b/src/libsystemd-network/sd-ipv4ll.c
@@ -25,6 +25,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "sd-id128.h"
 #include "sd-ipv4acd.h"
 #include "sd-ipv4ll.h"
 
diff --git a/src/libsystemd-network/test-lldp.c b/src/libsystemd-network/test-lldp.c
index c62689373f..b91797cb66 100644
--- a/src/libsystemd-network/test-lldp.c
+++ b/src/libsystemd-network/test-lldp.c
@@ -20,6 +20,7 @@
 ***/
 
 #include <arpa/inet.h>
+#include <errno.h>
 #include <net/ethernet.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/src/libsystemd/sd-bus/bus-control.c b/src/libsystemd/sd-bus/bus-control.c
index c6e3bf99fb..da4ed7b127 100644
--- a/src/libsystemd/sd-bus/bus-control.c
+++ b/src/libsystemd/sd-bus/bus-control.c
@@ -33,6 +33,7 @@
 #include "bus-message.h"
 #include "bus-util.h"
 #include "capability-util.h"
+#include "process-util.h"
 #include "stdio-util.h"
 #include "string-util.h"
 #include "strv.h"
diff --git a/src/libsystemd/sd-bus/bus-gvariant.c b/src/libsystemd/sd-bus/bus-gvariant.c
index 6a990a02c0..e6ab984d1f 100644
--- a/src/libsystemd/sd-bus/bus-gvariant.c
+++ b/src/libsystemd/sd-bus/bus-gvariant.c
@@ -18,6 +18,11 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
+#include <string.h>
+
+#include "sd-bus.h"
+
 #include "bus-gvariant.h"
 #include "bus-signature.h"
 #include "bus-type.h"
diff --git a/src/libsystemd/sd-bus/bus-signature.c b/src/libsystemd/sd-bus/bus-signature.c
index d16461f4ae..f3cd9bd0fa 100644
--- a/src/libsystemd/sd-bus/bus-signature.c
+++ b/src/libsystemd/sd-bus/bus-signature.c
@@ -20,6 +20,8 @@
 
 #include <util.h>
 
+#include "sd-bus.h"
+
 #include "bus-signature.h"
 #include "bus-type.h"
 
diff --git a/src/libsystemd/sd-bus/bus-socket.c b/src/libsystemd/sd-bus/bus-socket.c
index 61539313bc..cc52bfdd07 100644
--- a/src/libsystemd/sd-bus/bus-socket.c
+++ b/src/libsystemd/sd-bus/bus-socket.c
@@ -38,6 +38,7 @@
 #include "macro.h"
 #include "missing.h"
 #include "path-util.h"
+#include "process-util.h"
 #include "selinux-util.h"
 #include "signal-util.h"
 #include "stdio-util.h"
diff --git a/src/libsystemd/sd-bus/bus-type.c b/src/libsystemd/sd-bus/bus-type.c
index fe486f441d..980b35d8ea 100644
--- a/src/libsystemd/sd-bus/bus-type.c
+++ b/src/libsystemd/sd-bus/bus-type.c
@@ -18,6 +18,10 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
+
+#include "sd-bus.h"
+
 #include "bus-type.h"
 
 bool bus_type_is_valid(char c) {
diff --git a/src/libsystemd/sd-bus/bus-type.h b/src/libsystemd/sd-bus/bus-type.h
index ae272b1e6a..834f09777a 100644
--- a/src/libsystemd/sd-bus/bus-type.h
+++ b/src/libsystemd/sd-bus/bus-type.h
@@ -22,8 +22,6 @@
 
 #include <stdbool.h>
 
-#include "sd-bus.h"
-
 #include "macro.h"
 
 bool bus_type_is_valid(char c) _const_;
diff --git a/src/libsystemd/sd-bus/sd-bus.c b/src/libsystemd/sd-bus/sd-bus.c
index 8c8853c7ee..e723960e9f 100644
--- a/src/libsystemd/sd-bus/sd-bus.c
+++ b/src/libsystemd/sd-bus/sd-bus.c
@@ -50,6 +50,7 @@
 #include "macro.h"
 #include "missing.h"
 #include "parse-util.h"
+#include "process-util.h"
 #include "string-util.h"
 #include "strv.h"
 #include "util.h"
diff --git a/src/libsystemd/sd-bus/test-bus-track.c b/src/libsystemd/sd-bus/test-bus-track.c
index 320e8347f4..94c9d09de3 100644
--- a/src/libsystemd/sd-bus/test-bus-track.c
+++ b/src/libsystemd/sd-bus/test-bus-track.c
@@ -18,6 +18,9 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
+#include <sys/socket.h>
+
 #include "sd-bus.h"
 
 #include "macro.h"
diff --git a/src/libsystemd/sd-daemon/sd-daemon.c b/src/libsystemd/sd-daemon/sd-daemon.c
index ba383e0b3b..93721a5cf4 100644
--- a/src/libsystemd/sd-daemon/sd-daemon.c
+++ b/src/libsystemd/sd-daemon/sd-daemon.c
@@ -39,6 +39,7 @@
 #include "fs-util.h"
 #include "parse-util.h"
 #include "path-util.h"
+#include "process-util.h"
 #include "socket-util.h"
 #include "strv.h"
 #include "util.h"
diff --git a/src/libsystemd/sd-event/test-event.c b/src/libsystemd/sd-event/test-event.c
index 87a0c8522d..9873ae4a58 100644
--- a/src/libsystemd/sd-event/test-event.c
+++ b/src/libsystemd/sd-event/test-event.c
@@ -27,6 +27,7 @@
 #include "macro.h"
 #include "signal-util.h"
 #include "util.h"
+#include "process-util.h"
 
 static int prepare_handler(sd_event_source *s, void *userdata) {
         log_info("preparing %c", PTR_TO_INT(userdata));
diff --git a/src/libsystemd/sd-id128/id128-util.c b/src/libsystemd/sd-id128/id128-util.c
index 5541e8d47e..a6e38578b1 100644
--- a/src/libsystemd/sd-id128/id128-util.c
+++ b/src/libsystemd/sd-id128/id128-util.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <fcntl.h>
 #include <unistd.h>
 
diff --git a/src/libsystemd/sd-netlink/sd-netlink.c b/src/libsystemd/sd-netlink/sd-netlink.c
index d3c4e7130a..116e287bb6 100644
--- a/src/libsystemd/sd-netlink/sd-netlink.c
+++ b/src/libsystemd/sd-netlink/sd-netlink.c
@@ -30,6 +30,7 @@
 #include "missing.h"
 #include "netlink-internal.h"
 #include "netlink-util.h"
+#include "process-util.h"
 #include "socket-util.h"
 #include "util.h"
 
diff --git a/src/libsystemd/sd-resolve/sd-resolve.c b/src/libsystemd/sd-resolve/sd-resolve.c
index 6ed50b4e4a..787642a7fb 100644
--- a/src/libsystemd/sd-resolve/sd-resolve.c
+++ b/src/libsystemd/sd-resolve/sd-resolve.c
@@ -40,6 +40,7 @@
 #include "missing.h"
 #include "socket-util.h"
 #include "util.h"
+#include "process-util.h"
 
 #define WORKERS_MIN 1U
 #define WORKERS_MAX 16U
diff --git a/src/login/logind-core.c b/src/login/logind-core.c
index adeba746f5..e338682f41 100644
--- a/src/login/logind-core.c
+++ b/src/login/logind-core.c
@@ -31,6 +31,7 @@
 #include "fd-util.h"
 #include "logind.h"
 #include "parse-util.h"
+#include "process-util.h"
 #include "strv.h"
 #include "terminal-util.h"
 #include "udev-util.h"
diff --git a/src/login/logind.c b/src/login/logind.c
index cbaaa48e5a..d15d4cec5b 100644
--- a/src/login/logind.c
+++ b/src/login/logind.c
@@ -29,17 +29,18 @@
 #include "alloc-util.h"
 #include "bus-error.h"
 #include "bus-util.h"
+#include "cgroup-util.h"
 #include "conf-parser.h"
 #include "def.h"
 #include "dirent-util.h"
 #include "fd-util.h"
 #include "format-util.h"
 #include "logind.h"
+#include "process-util.h"
 #include "selinux-util.h"
 #include "signal-util.h"
 #include "strv.h"
 #include "udev-util.h"
-#include "cgroup-util.h"
 
 static void manager_free(Manager *m);
 
diff --git a/src/network/netdev/tuntap.c b/src/network/netdev/tuntap.c
index 4597a7feeb..4fc9b610af 100644
--- a/src/network/netdev/tuntap.c
+++ b/src/network/netdev/tuntap.c
@@ -18,6 +18,7 @@
     along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <fcntl.h>
 #include <linux/if_tun.h>
 #include <net/if.h>
diff --git a/src/network/netdev/veth.c b/src/network/netdev/veth.c
index 9220b3200f..2a2f50e345 100644
--- a/src/network/netdev/veth.c
+++ b/src/network/netdev/veth.c
@@ -18,8 +18,9 @@
     along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <net/if.h>
+#include <errno.h>
 #include <linux/veth.h>
+#include <net/if.h>
 
 #include "sd-netlink.h"
 
diff --git a/src/network/netdev/vlan.c b/src/network/netdev/vlan.c
index 3a0100d7e6..e7c0e7602a 100644
--- a/src/network/netdev/vlan.c
+++ b/src/network/netdev/vlan.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <linux/if_vlan.h>
 #include <net/if.h>
 
diff --git a/src/nspawn/nspawn-settings.h b/src/nspawn/nspawn-settings.h
index c0c5a153b0..10b8a63052 100644
--- a/src/nspawn/nspawn-settings.h
+++ b/src/nspawn/nspawn-settings.h
@@ -22,6 +22,8 @@
 
 #include <stdio.h>
 
+#include "sd-id128.h"
+
 #include "macro.h"
 #include "nspawn-expose-ports.h"
 #include "nspawn-mount.h"
diff --git a/src/nspawn/nspawn-setuid.c b/src/nspawn/nspawn-setuid.c
index cb1be273f4..b08bcd988a 100644
--- a/src/nspawn/nspawn-setuid.c
+++ b/src/nspawn/nspawn-setuid.c
@@ -23,6 +23,7 @@
 #include <unistd.h>
 
 #include "alloc-util.h"
+#include "errno.h"
 #include "fd-util.h"
 #include "mkdir.h"
 #include "nspawn-setuid.h"
diff --git a/src/partition/makefs.c b/src/partition/makefs.c
index 2ed31ac7ab..a957967dfe 100644
--- a/src/partition/makefs.c
+++ b/src/partition/makefs.c
@@ -28,6 +28,7 @@
 
 #include "alloc-util.h"
 #include "dissect-image.h"
+#include "process-util.h"
 #include "signal-util.h"
 #include "string-util.h"
 
diff --git a/src/resolve/dns-type.c b/src/resolve/dns-type.c
index 347252a90f..0c366b5e8e 100644
--- a/src/resolve/dns-type.c
+++ b/src/resolve/dns-type.c
@@ -19,6 +19,7 @@
 ***/
 
 #include <sys/socket.h>
+#include <errno.h>
 
 #include "dns-type.h"
 #include "parse-util.h"
diff --git a/src/resolve/test-dns-packet.c b/src/resolve/test-dns-packet.c
index 458c908fad..c1f118fecc 100644
--- a/src/resolve/test-dns-packet.c
+++ b/src/resolve/test-dns-packet.c
@@ -21,6 +21,8 @@
 #include <net/if.h>
 #include <glob.h>
 
+#include "sd-id128.h"
+
 #include "alloc-util.h"
 #include "fileio.h"
 #include "glob-util.h"
diff --git a/src/shared/bootspec.c b/src/shared/bootspec.c
index 4f255f620b..9c3bdd47de 100644
--- a/src/shared/bootspec.c
+++ b/src/shared/bootspec.c
@@ -20,6 +20,8 @@
 #include <stdio.h>
 #include <linux/magic.h>
 
+#include "sd-id128.h"
+
 #include "alloc-util.h"
 #include "blkid-util.h"
 #include "bootspec.h"
diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c
index 35b2c56555..1f0579f548 100644
--- a/src/shared/dissect-image.c
+++ b/src/shared/dissect-image.c
@@ -22,6 +22,8 @@
 #include <sys/prctl.h>
 #include <sys/wait.h>
 
+#include "sd-id128.h"
+
 #include "architecture.h"
 #include "ask-password-api.h"
 #include "blkid-util.h"
diff --git a/src/shared/dissect-image.h b/src/shared/dissect-image.h
index 53a1554a28..10e251ff09 100644
--- a/src/shared/dissect-image.h
+++ b/src/shared/dissect-image.h
@@ -22,6 +22,8 @@
 
 #include <stdbool.h>
 
+#include "sd-id128.h"
+
 #include "macro.h"
 
 typedef struct DissectedImage DissectedImage;
diff --git a/src/shared/loop-util.c b/src/shared/loop-util.c
index 097de690e5..37b8479f88 100644
--- a/src/shared/loop-util.c
+++ b/src/shared/loop-util.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <fcntl.h>
 #include <linux/loop.h>
 #include <sys/ioctl.h>
diff --git a/src/shared/test-tables.h b/src/shared/test-tables.h
index 6b223b1ee5..dd8bf0b582 100644
--- a/src/shared/test-tables.h
+++ b/src/shared/test-tables.h
@@ -20,6 +20,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 typedef const char* (*lookup_t)(int);
 typedef int (*reverse_t)(const char*);
diff --git a/src/shared/volatile-util.c b/src/shared/volatile-util.c
index 85512d00af..c92ad0adc0 100644
--- a/src/shared/volatile-util.c
+++ b/src/shared/volatile-util.c
@@ -18,6 +18,8 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
+
 #include "alloc-util.h"
 #include "macro.h"
 #include "parse-util.h"
diff --git a/src/test/test-cgroup.c b/src/test/test-cgroup.c
index 2ae95db162..b2440fc3a9 100644
--- a/src/test/test-cgroup.c
+++ b/src/test/test-cgroup.c
@@ -23,6 +23,7 @@
 
 #include "cgroup-util.h"
 #include "path-util.h"
+#include "process-util.h"
 #include "string-util.h"
 #include "util.h"
 
diff --git a/src/test/test-extract-word.c b/src/test/test-extract-word.c
index 84ab083e87..3e7c197cfe 100644
--- a/src/test/test-extract-word.c
+++ b/src/test/test-extract-word.c
@@ -19,6 +19,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 
diff --git a/src/test/test-hash.c b/src/test/test-hash.c
index f3b4258d6b..0366727476 100644
--- a/src/test/test-hash.c
+++ b/src/test/test-hash.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <stdio.h>
 
 #include "alloc-util.h"
diff --git a/src/test/test-hexdecoct.c b/src/test/test-hexdecoct.c
index 4f19cb406f..3e25a0bac8 100644
--- a/src/test/test-hexdecoct.c
+++ b/src/test/test-hexdecoct.c
@@ -18,6 +18,8 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
+
 #include "alloc-util.h"
 #include "hexdecoct.h"
 #include "macro.h"
diff --git a/src/test/test-log.c b/src/test/test-log.c
index 9468349cba..fd19899480 100644
--- a/src/test/test-log.c
+++ b/src/test/test-log.c
@@ -23,6 +23,7 @@
 
 #include "format-util.h"
 #include "log.h"
+#include "process-util.h"
 #include "util.h"
 
 assert_cc(LOG_REALM_REMOVE_LEVEL(LOG_REALM_PLUS_LEVEL(LOG_REALM_SYSTEMD, LOG_FTP | LOG_DEBUG))
diff --git a/src/test/test-ns.c b/src/test/test-ns.c
index 76e2b38b17..87b4facb85 100644
--- a/src/test/test-ns.c
+++ b/src/test/test-ns.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <stdlib.h>
 #include <unistd.h>
 
diff --git a/src/test/test-parse-util.c b/src/test/test-parse-util.c
index 8259e133c3..9375002133 100644
--- a/src/test/test-parse-util.c
+++ b/src/test/test-parse-util.c
@@ -19,6 +19,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <locale.h>
 #include <math.h>
 
diff --git a/src/test/test-signal-util.c b/src/test/test-signal-util.c
index 13a1d2ba1f..f4b19ed69d 100644
--- a/src/test/test-signal-util.c
+++ b/src/test/test-signal-util.c
@@ -23,6 +23,7 @@
 
 #include "macro.h"
 #include "signal-util.h"
+#include "process-util.h"
 
 static void test_block_signals(void) {
         sigset_t ss;
diff --git a/src/test/test-sizeof.c b/src/test/test-sizeof.c
index cc07dc3634..aed6db8423 100644
--- a/src/test/test-sizeof.c
+++ b/src/test/test-sizeof.c
@@ -19,6 +19,7 @@
 ***/
 
 #include <stdio.h>
+#include <string.h>
 
 #include "time-util.h"
 
diff --git a/src/test/test-socket-util.c b/src/test/test-socket-util.c
index 5b1574e8ea..d1ab7486ed 100644
--- a/src/test/test-socket-util.c
+++ b/src/test/test-socket-util.c
@@ -28,6 +28,7 @@
 #include "in-addr-util.h"
 #include "log.h"
 #include "macro.h"
+#include "process-util.h"
 #include "socket-util.h"
 #include "string-util.h"
 #include "util.h"
diff --git a/src/test/test-tmpfiles.c b/src/test/test-tmpfiles.c
index c479eccb8b..8e57fe0461 100644
--- a/src/test/test-tmpfiles.c
+++ b/src/test/test-tmpfiles.c
@@ -29,6 +29,7 @@
 #include "format-util.h"
 #include "fs-util.h"
 #include "log.h"
+#include "process-util.h"
 #include "string-util.h"
 #include "util.h"
 
diff --git a/src/test/test-util.c b/src/test/test-util.c
index 2124511bf0..21d90f0888 100644
--- a/src/test/test-util.c
+++ b/src/test/test-util.c
@@ -28,6 +28,7 @@
 #include "fileio.h"
 #include "fs-util.h"
 #include "parse-util.h"
+#include "process-util.h"
 #include "raw-clone.h"
 #include "rm-rf.h"
 #include "string-util.h"
diff --git a/src/test/test-watchdog.c b/src/test/test-watchdog.c
index e068d1ddd4..ffcf408f57 100644
--- a/src/test/test-watchdog.c
+++ b/src/test/test-watchdog.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <string.h>
 #include <unistd.h>
 
 #include "env-util.h"
diff --git a/src/udev/udevadm-control.c b/src/udev/udevadm-control.c
index d80d61583d..9546a6ebaf 100644
--- a/src/udev/udevadm-control.c
+++ b/src/udev/udevadm-control.c
@@ -21,6 +21,7 @@
 #include <string.h>
 #include <unistd.h>
 
+#include "process-util.h"
 #include "time-util.h"
 #include "udev-util.h"
 #include "udev.h"
diff --git a/src/veritysetup/veritysetup-generator.c b/src/veritysetup/veritysetup-generator.c
index c29c6f0bb3..24bee41243 100644
--- a/src/veritysetup/veritysetup-generator.c
+++ b/src/veritysetup/veritysetup-generator.c
@@ -18,6 +18,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <sys/stat.h>
diff --git a/src/veritysetup/veritysetup.c b/src/veritysetup/veritysetup.c
index d3066ca429..3b4e72bf9e 100644
--- a/src/veritysetup/veritysetup.c
+++ b/src/veritysetup/veritysetup.c
@@ -18,14 +18,15 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <errno.h>
 #include <stdio.h>
 #include <sys/stat.h>
 
-#include "crypt-util.h"
-#include "log.h"
-#include "hexdecoct.h"
-#include "string-util.h"
 #include "alloc-util.h"
+#include "crypt-util.h"
+#include "hexdecoct.h"
+#include "log.h"
+#include "string-util.h"
 
 static char *arg_root_hash = NULL;
 static char *arg_data_what = NULL;