diff --git a/lib/string/sprintf.c b/lib/string/sprintf.c
index 5b421ad0..cf3c210b 100644
--- a/lib/string/sprintf.c
+++ b/lib/string/sprintf.c
@@ -17,3 +17,8 @@
 extern inline int xasprintf(char **restrict s, const char *restrict fmt, ...);
 extern inline int xvasprintf(char **restrict s, const char *restrict fmt,
     va_list ap);
+
+extern inline int snprintf_(char *restrict s, size_t size,
+    const char *restrict fmt, ...);
+extern inline int vsnprintf_(char *restrict s, size_t size,
+    const char *restrict fmt, va_list ap);
diff --git a/lib/string/sprintf.h b/lib/string/sprintf.h
index 33e0bc2d..74853694 100644
--- a/lib/string/sprintf.h
+++ b/lib/string/sprintf.h
@@ -20,14 +20,7 @@
 
 
 #define SNPRINTF(s, fmt, ...)                                                 \
-({                                                                            \
-	size_t  sz_, len_;                                                    \
-                                                                              \
-	sz_ = NITEMS(s);                                                      \
-	len_ = snprintf(s, sz_, fmt __VA_OPT__(,) __VA_ARGS__);               \
-                                                                              \
-	(len_ >= sz_) ? -1 : len_;                                            \
-})
+	snprintf_(s, NITEMS(s), fmt __VA_OPT__(,) __VA_ARGS__)
 
 
 format_attr(printf, 2, 3)
@@ -35,6 +28,13 @@ inline int xasprintf(char **restrict s, const char *restrict fmt, ...);
 format_attr(printf, 2, 0)
 inline int xvasprintf(char **restrict s, const char *restrict fmt, va_list ap);
 
+format_attr(printf, 3, 4)
+inline int snprintf_(char *restrict s, size_t size, const char *restrict fmt,
+    ...);
+format_attr(printf, 3, 0)
+inline int vsnprintf_(char *restrict s, size_t size, const char *restrict fmt,
+    va_list ap);
+
 
 inline int
 xasprintf(char **restrict s, const char *restrict fmt, ...)
@@ -65,4 +65,33 @@ xvasprintf(char **restrict s, const char *restrict fmt, va_list ap)
 }
 
 
+inline int
+snprintf_(char *restrict s, size_t size, const char *restrict fmt, ...)
+{
+	int      len;
+	va_list  ap;
+
+	va_start(ap, fmt);
+	len = vsnprintf_(s, size, fmt, ap);
+	va_end(ap);
+
+	return len;
+}
+
+
+inline int
+vsnprintf_(char *restrict s, size_t size, const char *restrict fmt, va_list ap)
+{
+	int  len;
+
+	len = vsnprintf(s, size, fmt, ap);
+	if (len == -1)
+		return -1;
+	if ((size_t) len >= size)
+		return -1;
+
+	return len;
+}
+
+
 #endif  // include guard