diff --git a/lib/Makefile.am b/lib/Makefile.am
index b5f601a6b..bcf859833 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -33,6 +33,8 @@ libshadow_la_SOURCES = \
 	alloc.h \
 	atoi/a2i.c \
 	atoi/a2i.h \
+	atoi/getnum.c \
+	atoi/getnum.h \
 	atoi/str2i.c \
 	atoi/str2i.h \
 	atoi/strtoi.c \
@@ -71,7 +73,6 @@ libshadow_la_SOURCES = \
 	find_new_sub_gids.c \
 	find_new_sub_uids.c \
 	fputsx.c \
-	get_gid.c \
 	get_pid.c \
 	get_uid.c \
 	getdate.h \
diff --git a/lib/atoi/getnum.c b/lib/atoi/getnum.c
new file mode 100644
index 000000000..77dd23123
--- /dev/null
+++ b/lib/atoi/getnum.c
@@ -0,0 +1,13 @@
+// SPDX-FileCopyrightText: 2009, Nicolas François
+// SPDX-FileCopyrightText: 2023-2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#include <config.h>
+
+#include <sys/types.h>
+
+#include "atoi/getnum.h"
+
+
+extern inline int get_gid(const char *restrict gidstr, gid_t *restrict gid);
diff --git a/lib/get_gid.c b/lib/atoi/getnum.h
similarity index 50%
rename from lib/get_gid.c
rename to lib/atoi/getnum.h
index 6975792ec..c6f93b84b 100644
--- a/lib/get_gid.c
+++ b/lib/atoi/getnum.h
@@ -3,19 +3,29 @@
 // SPDX-License-Identifier: BSD-3-Clause
 
 
-#include <config.h>
+#ifndef SHADOW_INCLUDE_LIB_ATOI_GETNUM_H_
+#define SHADOW_INCLUDE_LIB_ATOI_GETNUM_H_
+
 
-#ident "$Id$"
+#include <config.h>
 
+#include <stddef.h>
 #include <sys/types.h>
 
-#include "prototypes.h"
 #include "atoi/a2i.h"
+#include "attr.h"
 #include "typetraits.h"
 
 
-int
-get_gid(const char *gidstr, gid_t *gid)
+ATTR_STRING(1) ATTR_ACCESS(write_only, 2)
+inline int get_gid(const char *restrict gidstr, gid_t *restrict gid);
+
+
+inline int
+get_gid(const char *restrict gidstr, gid_t *restrict gid)
 {
 	return a2i(gid_t, gid, gidstr, NULL, 10, type_min(gid_t), type_max(gid_t));
 }
+
+
+#endif  // include guard
diff --git a/lib/prototypes.h b/lib/prototypes.h
index 91ff368b7..40e76625c 100644
--- a/lib/prototypes.h
+++ b/lib/prototypes.h
@@ -142,10 +142,6 @@ extern int find_new_sub_gids (gid_t *range_start, unsigned long *range_count);
 extern int find_new_sub_uids (uid_t *range_start, unsigned long *range_count);
 #endif				/* ENABLE_SUBIDS */
 
-
-/* get_gid.c */
-extern int get_gid (const char *gidstr, gid_t *gid);
-
 /* getgr_nam_gid.c */
 extern /*@only@*//*@null@*/struct group *getgr_nam_gid (/*@null@*/const char *grname);
 
diff --git a/lib/sgetgrent.c b/lib/sgetgrent.c
index 6cde15c3f..26ddf5c2a 100644
--- a/lib/sgetgrent.c
+++ b/lib/sgetgrent.c
@@ -17,9 +17,11 @@
 #include <string.h>
 
 #include "alloc.h"
+#include "atoi/getnum.h"
 #include "defines.h"
 #include "prototypes.h"
 
+
 #define	NFIELDS	4
 
 /*
diff --git a/lib/sgetpwent.c b/lib/sgetpwent.c
index 75c91770b..ad9ace3c5 100644
--- a/lib/sgetpwent.c
+++ b/lib/sgetpwent.c
@@ -16,10 +16,12 @@
 #include <pwd.h>
 #include <string.h>
 
+#include "atoi/getnum.h"
 #include "defines.h"
 #include "prototypes.h"
 #include "shadowlog_internal.h"
 
+
 #define	NFIELDS	7
 
 /*
diff --git a/libsubid/api.c b/libsubid/api.c
index 76a9eec4d..feed2f7c2 100644
--- a/libsubid/api.c
+++ b/libsubid/api.c
@@ -12,11 +12,13 @@
 #include <string.h>
 #include <pwd.h>
 #include <stdbool.h>
+
 #include "subordinateio.h"
 #include "idmapping.h"
 #include "subid.h"
 #include "shadowlog.h"
 
+
 bool subid_init(const char *progname, FILE * logfd)
 {
 	FILE *shadow_logfd;
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 6d2c0521c..9ebbc017b 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -22,7 +22,6 @@ lib/find_new_sub_gids.c
 lib/find_new_sub_uids.c
 lib/find_new_uid.c
 lib/fputsx.c
-lib/get_gid.c
 lib/get_uid.c
 lib/getdef.c
 lib/getgr_nam_gid.c
diff --git a/src/groupadd.c b/src/groupadd.c
index 46e6550ae..095a41eed 100644
--- a/src/groupadd.c
+++ b/src/groupadd.c
@@ -23,6 +23,8 @@
 #include <pwd.h>
 #endif				/* USE_PAM */
 #endif				/* ACCT_TOOLS_SETUID */
+
+#include "atoi/getnum.h"
 #include "chkname.h"
 #include "defines.h"
 #include "getdef.h"
@@ -37,6 +39,7 @@
 #include "shadowlog.h"
 #include "run_part.h"
 
+
 /*
  * exit status values
  */
diff --git a/src/groupmod.c b/src/groupmod.c
index 989d7ea34..d7aaf6660 100644
--- a/src/groupmod.c
+++ b/src/groupmod.c
@@ -27,6 +27,7 @@
 #endif				/* ACCT_TOOLS_SETUID */
 
 #include "alloc.h"
+#include "atoi/getnum.h"
 #include "chkname.h"
 #include "defines.h"
 #include "groupio.h"
@@ -40,6 +41,8 @@
 #include "shadowlog.h"
 #include "string/stpecpy.h"
 #include "string/stpeprintf.h"
+
+
 /*
  * exit status values
  */
diff --git a/src/newusers.c b/src/newusers.c
index 0705b5797..47a587ec0 100644
--- a/src/newusers.c
+++ b/src/newusers.c
@@ -31,6 +31,7 @@
 #include <string.h>
 
 #include "alloc.h"
+#include "atoi/getnum.h"
 #include "atoi/str2i.h"
 #ifdef ACCT_TOOLS_SETUID
 #ifdef USE_PAM