4 files changed, 10 insertions, 6 deletions
diff --git a/src/grp-system/libcore/namespace.c b/src/grp-system/libcore/namespace.c
index cb85074cce..5af026ff99 100644
--- a/src/grp-system/libcore/namespace.c
+++ b/src/grp-system/libcore/namespace.c
@@ -18,13 +18,13 @@
 ***/
 
 #include <errno.h>
-#include <linux/fs.h>
 #include <sched.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <linux/fs.h>
 
 #include "basic/alloc-util.h"
 #include "basic/fd-util.h"
diff --git a/src/grp-system/libcore/target.c b/src/grp-system/libcore/target.c
index e62a49be84..74af0ced0c 100644
--- a/src/grp-system/libcore/target.c
+++ b/src/grp-system/libcore/target.c
@@ -23,7 +23,6 @@
 #include "basic/unit-name.h"
 
 #include "dbus-target.h"
-#include "target.h"
 #include "unit.h"
 
 static const UnitActiveState state_translation_table[_TARGET_STATE_MAX] = {
diff --git a/src/grp-system/libcore/target.h b/src/grp-system/libcore/target.h
index 339aea154e..9ac560ab17 100644
--- a/src/grp-system/libcore/target.h
+++ b/src/grp-system/libcore/target.h
@@ -19,6 +19,10 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#if __INCLUDE_LEVEL__ <= 1
+#error "Do not include target.h directly; use unit.h, which includes target.h."
+#endif
+
 typedef struct Target Target;
 
 struct Target {
diff --git a/src/grp-system/libcore/unit.h b/src/grp-system/libcore/unit.h
index df1174b837..79de5a8a89 100644
--- a/src/grp-system/libcore/unit.h
+++ b/src/grp-system/libcore/unit.h
@@ -23,16 +23,17 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include "shared/condition.h"
+#include "shared/install.h"
+#include "basic/list.h"
+#include "basic/unit-name.h"
+
 typedef struct Unit Unit;
 typedef struct UnitVTable UnitVTable;
 typedef struct UnitRef UnitRef;
 typedef struct UnitStatusMessageFormats UnitStatusMessageFormats;
 
-#include "shared/condition.h"
 #include "failure-action.h"
-#include "shared/install.h"
-#include "basic/list.h"
-#include "basic/unit-name.h"
 
 typedef enum KillOperation {
         KILL_TERMINATE,