diff --git a/lib/Makefile.am b/lib/Makefile.am
index a713f98c..231ed326 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -160,6 +160,8 @@ libshadow_la_SOURCES = \
 	string/strcpy/strtcpy.h \
 	string/strdup/strndupa.c \
 	string/strdup/strndupa.h \
+	string/strdup/xstrdup.c \
+	string/strdup/xstrdup.h \
 	string/strdup/xstrndup.c \
 	string/strdup/xstrndup.h \
 	string/strftime.c \
diff --git a/lib/alloc.c b/lib/alloc.c
index 962f45a1..a9cbcaf0 100644
--- a/lib/alloc.c
+++ b/lib/alloc.c
@@ -1,12 +1,9 @@
-/*
- * SPDX-FileCopyrightText: 1990 - 1994, Julianne Frances Haugh
- * SPDX-FileCopyrightText: 1996 - 1998, Marek Michałkiewicz
- * SPDX-FileCopyrightText: 2003 - 2006, Tomasz Kłoczko
- * SPDX-FileCopyrightText: 2008       , Nicolas François
- * SPDX-FileCopyrightText: 2023       , Alejandro Colomar <alx@kernel.org>
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
+// SPDX-FileCopyrightText: 1990-1994, Julianne Frances Haugh
+// SPDX-FileCopyrightText: 1996-1998, Marek Michałkiewicz
+// SPDX-FileCopyrightText: 2003-2006, Tomasz Kłoczko
+// SPDX-FileCopyrightText: 2008     , Nicolas François
+// SPDX-FileCopyrightText: 2023-2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
 
 /* Replacements for malloc and strdup with error checking.  Too trivial
    to be worth copyrighting :-).  I did that because a lot of code used
@@ -19,8 +16,6 @@
 
 #include <config.h>
 
-#ident "$Id$"
-
 #include "alloc.h"
 
 #include <errno.h>
@@ -36,7 +31,6 @@ extern inline void *xmalloc(size_t size);
 extern inline void *xmallocarray(size_t nmemb, size_t size);
 extern inline void *mallocarray(size_t nmemb, size_t size);
 extern inline void *reallocarrayf(void *p, size_t nmemb, size_t size);
-extern inline char *xstrdup(const char *str);
 
 
 void *
diff --git a/lib/alloc.h b/lib/alloc.h
index 39405a56..cf2e4b2e 100644
--- a/lib/alloc.h
+++ b/lib/alloc.h
@@ -15,7 +15,6 @@
 #include <stdlib.h>
 
 #include "attr.h"
-#include "defines.h"
 
 
 #define CALLOC(n, type)   ((type *) calloc(n, sizeof(type)))
@@ -47,8 +46,6 @@ ATTR_MALLOC(free)
 inline void *mallocarray(size_t nmemb, size_t size);
 ATTR_MALLOC(free)
 inline void *reallocarrayf(void *p, size_t nmemb, size_t size);
-ATTR_MALLOC(free)
-inline char *xstrdup(const char *str);
 
 ATTR_MALLOC(free)
 void *xcalloc(size_t nmemb, size_t size);
@@ -91,11 +88,4 @@ reallocarrayf(void *p, size_t nmemb, size_t size)
 }
 
 
-inline char *
-xstrdup(const char *str)
-{
-	return strcpy(XMALLOC(strlen(str) + 1, char), str);
-}
-
-
 #endif  // include guard
diff --git a/lib/env.c b/lib/env.c
index 8a59468a..2debf35c 100644
--- a/lib/env.c
+++ b/lib/env.c
@@ -22,6 +22,7 @@
 #include "shadowlog.h"
 #include "string/sprintf/snprintf.h"
 #include "string/sprintf/xasprintf.h"
+#include "string/strdup/xstrdup.h"
 
 
 /*
diff --git a/lib/list.c b/lib/list.c
index 9fc66089..8604cb63 100644
--- a/lib/list.c
+++ b/lib/list.c
@@ -15,6 +15,9 @@
 #include "alloc.h"
 #include "prototypes.h"
 #include "defines.h"
+#include "string/strdup/xstrdup.h"
+
+
 /*
  * add_list - add a member to a list of group members
  *
diff --git a/lib/motd.c b/lib/motd.c
index d1d5bf6e..52712675 100644
--- a/lib/motd.c
+++ b/lib/motd.c
@@ -13,10 +13,12 @@
 
 #include <stdio.h>
 
-#include "alloc.h"
 #include "defines.h"
 #include "getdef.h"
 #include "prototypes.h"
+#include "string/strdup/xstrdup.h"
+
+
 /*
  * motd -- output the /etc/motd file
  *
diff --git a/lib/obscure.c b/lib/obscure.c
index 32e8941c..136f26a6 100644
--- a/lib/obscure.c
+++ b/lib/obscure.c
@@ -15,13 +15,14 @@
 #include <ctype.h>
 #include <stdio.h>
 
-#include "alloc.h"
 #include "attr.h"
 #include "memzero.h"
 #include "prototypes.h"
 #include "defines.h"
 #include "getdef.h"
 #include "string/sprintf/xasprintf.h"
+#include "string/strdup/xstrdup.h"
+
 
 #if WITH_LIBBSD == 0
 #include "freezero.h"
diff --git a/lib/setupenv.c b/lib/setupenv.c
index 8c58ac53..8eda5d58 100644
--- a/lib/setupenv.c
+++ b/lib/setupenv.c
@@ -21,13 +21,13 @@
 #include <stdio.h>
 #include <ctype.h>
 
-#include "alloc.h"
 #include "prototypes.h"
 #include "defines.h"
 #include <pwd.h>
 #include "getdef.h"
 #include "shadowlog.h"
 #include "string/sprintf/xasprintf.h"
+#include "string/strdup/xstrdup.h"
 
 
 #ifndef USE_PAM
diff --git a/lib/string/strdup/xstrdup.c b/lib/string/strdup/xstrdup.c
new file mode 100644
index 00000000..00ec9db3
--- /dev/null
+++ b/lib/string/strdup/xstrdup.c
@@ -0,0 +1,14 @@
+// SPDX-FileCopyrightText: 1990-1994, Julianne Frances Haugh
+// SPDX-FileCopyrightText: 1996-1998, Marek Michałkiewicz
+// SPDX-FileCopyrightText: 2003-2006, Tomasz Kłoczko
+// SPDX-FileCopyrightText: 2008     , Nicolas François
+// SPDX-FileCopyrightText: 2023-2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#include <config.h>
+
+#include "string/strdup/xstrdup.h"
+
+
+extern inline char *xstrdup(const char *str);
diff --git a/lib/string/strdup/xstrdup.h b/lib/string/strdup/xstrdup.h
new file mode 100644
index 00000000..13164182
--- /dev/null
+++ b/lib/string/strdup/xstrdup.h
@@ -0,0 +1,32 @@
+// SPDX-FileCopyrightText: 1990-1994, Julianne Frances Haugh
+// SPDX-FileCopyrightText: 1996-1998, Marek Michałkiewicz
+// SPDX-FileCopyrightText: 2003-2006, Tomasz Kłoczko
+// SPDX-FileCopyrightText: 2008     , Nicolas François
+// SPDX-FileCopyrightText: 2023-2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#ifndef SHADOW_INCLUDE_LIB_STRING_STRDUP_XSTRDUP_H_
+#define SHADOW_INCLUDE_LIB_STRING_STRDUP_XSTRDUP_H_
+
+
+#include <config.h>
+
+#include <string.h>
+
+#include "alloc.h"
+#include "attr.h"
+
+
+ATTR_MALLOC(free)
+inline char *xstrdup(const char *str);
+
+
+inline char *
+xstrdup(const char *str)
+{
+	return strcpy(XMALLOC(strlen(str) + 1, char), str);
+}
+
+
+#endif  // include guard
diff --git a/lib/utmp.c b/lib/utmp.c
index 40c32c18..ba80f7fd 100644
--- a/lib/utmp.c
+++ b/lib/utmp.c
@@ -26,6 +26,7 @@
 #include "sizeof.h"
 #include "string/strcpy/strncpy.h"
 #include "string/strcpy/strtcpy.h"
+#include "string/strdup/xstrdup.h"
 #include "string/strdup/xstrndup.h"
 
 #ident "$Id$"
diff --git a/src/chage.c b/src/chage.c
index b8af89cf..9b85b425 100644
--- a/src/chage.c
+++ b/src/chage.c
@@ -26,7 +26,6 @@
 #endif				/* ACCT_TOOLS_SETUID */
 #include <pwd.h>
 
-#include "alloc.h"
 #include "atoi/str2i.h"
 #include "defines.h"
 #include "memzero.h"
@@ -36,6 +35,7 @@
 #include "shadowlog.h"
 #include "string/sprintf/snprintf.h"
 #include "string/strcpy/strtcpy.h"
+#include "string/strdup/xstrdup.h"
 #include "string/strftime.h"
 #include "time/day_to_str.h"
 /*@-exitarg@*/
diff --git a/src/chfn.c b/src/chfn.c
index e78037d3..1872b2df 100644
--- a/src/chfn.c
+++ b/src/chfn.c
@@ -18,7 +18,6 @@
 #include <sys/types.h>
 #include <getopt.h>
 
-#include "alloc.h"
 #include "defines.h"
 #include "getdef.h"
 #include "nscd.h"
@@ -34,6 +33,7 @@
 #include "shadowlog.h"
 #include "string/sprintf/snprintf.h"
 #include "string/strcpy/strtcpy.h"
+#include "string/strdup/xstrdup.h"
 
 
 /*
diff --git a/src/chsh.c b/src/chsh.c
index c211c7a0..4e85678d 100644
--- a/src/chsh.c
+++ b/src/chsh.c
@@ -17,7 +17,6 @@
 #include <stdio.h>
 #include <sys/types.h>
 
-#include "alloc.h"
 #include "defines.h"
 #include "getdef.h"
 #include "nscd.h"
@@ -32,6 +31,7 @@
 #include "exitcodes.h"
 #include "shadowlog.h"
 #include "string/strcpy/strtcpy.h"
+#include "string/strdup/xstrdup.h"
 
 #ifndef SHELLS_FILE
 #define SHELLS_FILE "/etc/shells"
diff --git a/src/gpasswd.c b/src/gpasswd.c
index 0dc3a5f2..70d7547f 100644
--- a/src/gpasswd.c
+++ b/src/gpasswd.c
@@ -37,6 +37,7 @@
 #include "shadowlog.h"
 #include "string/sprintf/snprintf.h"
 #include "string/strcpy/strtcpy.h"
+#include "string/strdup/xstrdup.h"
 
 
 /*
diff --git a/src/groupmems.c b/src/groupmems.c
index 0d0882db..444882cc 100644
--- a/src/groupmems.c
+++ b/src/groupmems.c
@@ -27,6 +27,8 @@
 #include "sgroupio.h"
 #endif
 #include "shadowlog.h"
+#include "string/strdup/xstrdup.h"
+
 
 /* Exit Status Values */
 /*@-exitarg@*/
diff --git a/src/groupmod.c b/src/groupmod.c
index e39b76b8..3f6d54eb 100644
--- a/src/groupmod.c
+++ b/src/groupmod.c
@@ -41,6 +41,7 @@
 #include "shadowlog.h"
 #include "string/sprintf/stpeprintf.h"
 #include "string/strcpy/stpecpy.h"
+#include "string/strdup/xstrdup.h"
 
 
 /*
diff --git a/src/login.c b/src/login.c
index f9f8606f..338c1a43 100644
--- a/src/login.c
+++ b/src/login.c
@@ -40,6 +40,7 @@
 #include "shadowlog.h"
 #include "string/sprintf/snprintf.h"
 #include "string/strcpy/strtcpy.h"
+#include "string/strdup/xstrdup.h"
 #include "string/strftime.h"
 
 
diff --git a/src/newgrp.c b/src/newgrp.c
index b9aec21d..6542abf2 100644
--- a/src/newgrp.c
+++ b/src/newgrp.c
@@ -26,6 +26,7 @@
 #include "exitcodes.h"
 #include "shadowlog.h"
 #include "string/sprintf/snprintf.h"
+#include "string/strdup/xstrdup.h"
 
 
 /*
diff --git a/src/newusers.c b/src/newusers.c
index c28f8d89..e5d20491 100644
--- a/src/newusers.c
+++ b/src/newusers.c
@@ -53,6 +53,7 @@
 #include "chkname.h"
 #include "shadowlog.h"
 #include "string/sprintf/snprintf.h"
+#include "string/strdup/xstrdup.h"
 
 
 /*
diff --git a/src/passwd.c b/src/passwd.c
index e22788f5..c2468d40 100644
--- a/src/passwd.c
+++ b/src/passwd.c
@@ -20,7 +20,6 @@
 #include <sys/types.h>
 #include <time.h>
 
-#include "alloc.h"
 #include "agetpass.h"
 #include "atoi/str2i.h"
 #include "defines.h"
@@ -35,10 +34,10 @@
 #include "shadowlog.h"
 #include "string/sprintf/xasprintf.h"
 #include "string/strcpy/strtcpy.h"
+#include "string/strdup/xstrdup.h"
 #include "time/day_to_str.h"
 
 
-
 /*
  * exit status values
  */
diff --git a/src/su.c b/src/su.c
index cfc5ab1f..4e0d4100 100644
--- a/src/su.c
+++ b/src/su.c
@@ -62,6 +62,7 @@
 #include "string/sprintf/snprintf.h"
 #include "string/sprintf/xasprintf.h"
 #include "string/strcpy/strtcpy.h"
+#include "string/strdup/xstrdup.h"
 
 
 /*
diff --git a/src/sulogin.c b/src/sulogin.c
index 20971743..6af471b5 100644
--- a/src/sulogin.c
+++ b/src/sulogin.c
@@ -19,7 +19,6 @@
 #include <sys/types.h>
 
 #include "agetpass.h"
-#include "alloc.h"
 #include "attr.h"
 #include "defines.h"
 #include "getdef.h"
@@ -28,6 +27,7 @@
 /*@-exitarg@*/
 #include "exitcodes.h"
 #include "shadowlog.h"
+#include "string/strdup/xstrdup.h"
 
 
 /*
diff --git a/src/useradd.c b/src/useradd.c
index 52aed3ee..4db0aa3a 100644
--- a/src/useradd.c
+++ b/src/useradd.c
@@ -67,6 +67,7 @@
 #include "shadowlog.h"
 #include "string/sprintf/snprintf.h"
 #include "string/sprintf/xasprintf.h"
+#include "string/strdup/xstrdup.h"
 
 
 #ifndef SKEL_DIR
diff --git a/src/userdel.c b/src/userdel.c
index 38158d44..ead69604 100644
--- a/src/userdel.c
+++ b/src/userdel.c
@@ -20,7 +20,6 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#include "alloc.h"
 #ifdef ACCT_TOOLS_SETUID
 #ifdef USE_PAM
 #include "pam_defs.h"
@@ -53,6 +52,7 @@
 #endif				/* ENABLE_SUBIDS */
 #include "shadowlog.h"
 #include "string/sprintf/xasprintf.h"
+#include "string/strdup/xstrdup.h"
 
 
 /*
diff --git a/src/usermod.c b/src/usermod.c
index 1291814b..b688ee8e 100644
--- a/src/usermod.c
+++ b/src/usermod.c
@@ -62,6 +62,7 @@
 #endif
 #include "shadowlog.h"
 #include "string/sprintf/xasprintf.h"
+#include "string/strdup/xstrdup.h"
 #include "time/day_to_str.h"