diff --git a/lib/Makefile.am b/lib/Makefile.am
index 5b1121c4..baef9cd2 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -31,6 +31,8 @@ libshadow_la_SOURCES = \
 	agetpass.h \
 	alloc.c \
 	alloc.h \
+	atoi/strtoi.c \
+	atoi/strtoi.h \
 	atoi/strtou_noneg.c \
 	atoi/strtou_noneg.h \
 	attr.h \
diff --git a/lib/atoi/strtoi.c b/lib/atoi/strtoi.c
new file mode 100644
index 00000000..197707b1
--- /dev/null
+++ b/lib/atoi/strtoi.c
@@ -0,0 +1,15 @@
+// SPDX-FileCopyrightText: 2023, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#include <config.h>
+
+#include "atoi/strtoi.h"
+
+#include <stdint.h>
+
+
+extern inline intmax_t strtoi_(const char *s, char **restrict endp, int base,
+    intmax_t min, intmax_t max, int *restrict status);
+extern inline uintmax_t strtou_(const char *s, char **restrict endp, int base,
+    uintmax_t min, uintmax_t max, int *restrict status);
diff --git a/lib/atoi/strtoi.h b/lib/atoi/strtoi.h
new file mode 100644
index 00000000..1f061fc0
--- /dev/null
+++ b/lib/atoi/strtoi.h
@@ -0,0 +1,96 @@
+// SPDX-FileCopyrightText: 2023, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#ifndef SHADOW_INCLUDE_LIB_ATOI_STRTOI_H_
+#define SHADOW_INCLUDE_LIB_ATOI_STRTOI_H_
+
+
+#include <config.h>
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/param.h>
+
+#include "attr.h"
+
+
+#define strtoNmax(TYPE, ...)                                                  \
+(                                                                             \
+	_Generic((TYPE) 0,                                                    \
+		intmax_t:  strtoimax,                                         \
+		uintmax_t: strtoumax                                          \
+	)(__VA_ARGS__)                                                        \
+)
+
+
+#define strtoN(s, endp, base, min, max, status, TYPE)                         \
+({                                                                            \
+	const char  *s_ = s;                                                  \
+	char        **endp_ = endp;                                           \
+	int         base_ = base;                                             \
+	TYPE        min_ = min;                                               \
+	TYPE        max_ = max;                                               \
+	int         *status_ = status;                                        \
+                                                                              \
+	int         e_, st_;                                                  \
+	char        *end_;                                                    \
+	TYPE        n_;                                                       \
+                                                                              \
+	if (endp_ == NULL)                                                    \
+		endp_ = &end_;                                                \
+	if (status_ == NULL)                                                  \
+		status_ = &st_;                                               \
+                                                                              \
+	if (base_ != 0 && (base_ < 0 || base_ > 36)) {                        \
+		*status_ = EINVAL;                                            \
+		n_ = 0;                                                       \
+                                                                              \
+	} else {                                                              \
+		e_ = errno;                                                   \
+		errno = 0;                                                    \
+		n_ = strtoNmax(TYPE, s_, endp_, base_);                       \
+                                                                              \
+		if (*endp_ == s_)                                             \
+			*status_ = ECANCELED;                                 \
+		else if (errno == ERANGE || n_ < min_ || n_ > max_)           \
+			*status_ = ERANGE;                                    \
+		else if (**endp_ != '\0')                                     \
+			*status_ = ENOTSUP;                                   \
+		else                                                          \
+			*status_ = 0;                                         \
+                                                                              \
+		errno = e_;                                                   \
+	}                                                                     \
+	MAX(min_, MIN(max_, n_));                                             \
+})
+
+
+ATTR_STRING(1) ATTR_ACCESS(write_only, 2) ATTR_ACCESS(write_only, 6)
+inline intmax_t strtoi_(const char *s, char **restrict endp, int base,
+    intmax_t min, intmax_t max, int *restrict status);
+ATTR_STRING(1) ATTR_ACCESS(write_only, 2) ATTR_ACCESS(write_only, 6)
+inline uintmax_t strtou_(const char *s, char **restrict endp, int base,
+    uintmax_t min, uintmax_t max, int *restrict status);
+
+
+inline intmax_t
+strtoi_(const char *s, char **restrict endp, int base,
+    intmax_t min, intmax_t max, int *restrict status)
+{
+	return strtoN(s, endp, base, min, max, status, intmax_t);
+}
+
+
+inline uintmax_t
+strtou_(const char *s, char **restrict endp, int base,
+    uintmax_t min, uintmax_t max, int *restrict status)
+{
+	return strtoN(s, endp, base, min, max, status, uintmax_t);
+}
+
+
+#endif  // include guard