diff --git a/source/common.c b/source/common.c
index 0b275b9..83624ce 100644
--- a/source/common.c
+++ b/source/common.c
@@ -132,6 +132,25 @@ void InsertLinkAfter (link_t *l, link_t *after)
 ============================================================================
 */
 
+#define	snprintf_func		snprintf
+#define	vsnprintf_func		vsnprintf
+
+int q_vsnprintf(char *str, size_t size, const char *format, va_list args)
+{
+	int		ret;
+
+	ret = vsnprintf_func (str, size, format, args);
+
+	if (ret < 0)
+		ret = (int)size;
+	if (size == 0)	/* no buffer */
+		return ret;
+	if ((size_t)ret >= size)
+		str[size - 1] = '\0';
+
+	return ret;
+}
+
 int q_snprintf (char *str, size_t size, const char *format, ...)
 {
 	int		ret;
diff --git a/source/common.h b/source/common.h
index 35e50e7..680a4f2 100644
--- a/source/common.h
+++ b/source/common.h
@@ -155,6 +155,8 @@ int Q_strcasecmp (char *s1, char *s2);
 int Q_strncasecmp (char *s1, char *s2, int n);
 int	Q_atoi (char *str);
 float Q_atof (char *str);
+int q_snprintf (char *str, size_t size, const char *format, ...);
+int q_vsnprintf(char *str, size_t size, const char *format, va_list args);
 
 //============================================================================