1 files changed, 2 insertions, 2 deletions

diff --git a/src/minibuf.c b/src/minibuf.c
index ee3fbef5c91..033c598e0a1 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -1833,12 +1833,12 @@ Return nil if there is no valid completion, else t.")
      i gets index in string of where to stop completing.  */
   {
     int len, c;
-
+    int bytes = STRING_BYTES (XSTRING (completion));
     completion_string = XSTRING (completion)->data;
     for (; i_byte < STRING_BYTES (XSTRING (completion)); i_byte += len, i++)
       {
         c = STRING_CHAR_AND_LENGTH (completion_string + i_byte,
-                                    XSTRING (completion)->size - i_byte,
+                                    bytes - i_byte,
                                     len);
         if (SYNTAX (c) != Sword)
           {