diff --git a/src/eval.c b/src/eval.c
index a173cc7..6f8aa3c 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -5745,8 +5745,10 @@
 
 			      if (c == 'X')
 				  n = 2;
-			      else
+			      else if (*p == 'u')
 				  n = 4;
+			      else
+				  n = 8;
 			      nr = 0;
 			      while (--n >= 0 && vim_isxdigit(p[1]))
 			      {