diff --git a/src/basic/crypt-util.h b/src/basic/crypt-util.h
index 5b03cb072d..8c86714aec 100644
--- a/src/basic/crypt-util.h
+++ b/src/basic/crypt-util.h
@@ -1,4 +1,5 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
 
 #if HAVE_LIBCRYPTSETUP
 #include <libcryptsetup.h>
diff --git a/src/basic/exec-util.h b/src/basic/exec-util.h
index 8b1f18139c..823ca6578c 100644
--- a/src/basic/exec-util.h
+++ b/src/basic/exec-util.h
@@ -1,4 +1,5 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
 
 #include <stdbool.h>
 
diff --git a/src/fuzz/fuzz.h b/src/fuzz/fuzz.h
index e2bfab3168..1e56526259 100644
--- a/src/fuzz/fuzz.h
+++ b/src/fuzz/fuzz.h
@@ -1,4 +1,5 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
 
 #include <stddef.h>
 #include <stdint.h>
diff --git a/src/locale/keymap-util.h b/src/locale/keymap-util.h
index c55c9f92a6..902da689c8 100644
--- a/src/locale/keymap-util.h
+++ b/src/locale/keymap-util.h
@@ -1,4 +1,5 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
 
 #include "sd-bus.h"
 
diff --git a/src/portable/portabled-image-bus.h b/src/portable/portabled-image-bus.h
index 81c17f68af..825dea2682 100644
--- a/src/portable/portabled-image-bus.h
+++ b/src/portable/portabled-image-bus.h
@@ -1,4 +1,5 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
 
 #include "sd-bus.h"
 
diff --git a/src/portable/portabled-image.h b/src/portable/portabled-image.h
index f29bd89e83..26ce2f6b59 100644
--- a/src/portable/portabled-image.h
+++ b/src/portable/portabled-image.h
@@ -1,4 +1,5 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
 
 #include "hashmap.h"
 #include "machine-image.h"
diff --git a/src/resolve/resolvconf-compat.h b/src/resolve/resolvconf-compat.h
index 507ac3d222..872add1d56 100644
--- a/src/resolve/resolvconf-compat.h
+++ b/src/resolve/resolvconf-compat.h
@@ -1,3 +1,4 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
 
 int resolvconf_parse_argv(int argc, char *argv[]);
diff --git a/src/resolve/resolvectl.h b/src/resolve/resolvectl.h
index 6ecaa4ff31..9008daace5 100644
--- a/src/resolve/resolvectl.h
+++ b/src/resolve/resolvectl.h
@@ -1,4 +1,5 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
 
 #include <in-addr-util.h>
 #include <stdbool.h>
diff --git a/src/shared/journal-util.h b/src/shared/journal-util.h
index 404fa53b30..da86434a67 100644
--- a/src/shared/journal-util.h
+++ b/src/shared/journal-util.h
@@ -1,4 +1,5 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
 
 #include <stdbool.h>
 #include <sys/types.h>