diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index b8a2f54..4ee19d0 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -980,6 +980,11 @@
  *             [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
  *           little endian output byte order is:
  *             [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
+ * - 'V' For a struct va_format which contains a format string * and va_list *,
+ *       call vsnprintf(->format, *->va_list).
+ *       Implements a "recursive vsnprintf".
+ *       Do not use this feature without some mechanism to verify the
+ *       correctness of the format string and va_list arguments.
  *
  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
  * function pointers are really function descriptors, which contain a
@@ -1025,6 +1030,10 @@
 		break;
 	case 'U':
 		return uuid_string(buf, end, ptr, spec, fmt);
+	case 'V':
+		return buf + vsnprintf(buf, end - buf,
+				       ((struct va_format *)ptr)->fmt,
+				       *(((struct va_format *)ptr)->va));
 	}
 	spec.flags |= SMALL;
 	if (spec.field_width == -1) {