1 files changed, 6 insertions, 4 deletions

diff --git a/src/syntax.c b/src/syntax.c
index 56176f32418..1301c0689ad 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -1541,7 +1541,8 @@ skip_chars (int forwardp, Lisp_Object string, Lisp_Object lim, int handle_iso_cl
 
               if (c <= c2)
                 {
-                  while (c <= c2)
+                  unsigned lim2 = c2 + 1;
+                  while (c < lim2)
                     fastmap[c++] = 1;
                   if (! ASCII_CHAR_P (c2))
                     string_has_eight_bit = 1;
@@ -1681,7 +1682,8 @@ skip_chars (int forwardp, Lisp_Object string, Lisp_Object lim, int handle_iso_cl
                 }
               if (! ASCII_CHAR_P (c))
                 {
-                  while (leading_code <= leading_code2)
+                  unsigned lim2 = leading_code2 + 1;
+                  while (leading_code < lim2)
                     fastmap[leading_code++] = 1;
                   if (c <= c2)
                     {
@@ -1713,9 +1715,9 @@ skip_chars (int forwardp, Lisp_Object string, Lisp_Object lim, int handle_iso_cl
           for (i = 0; i < n_char_ranges; i += 2)
             {
               int c1 = char_ranges[i];
-              int c2 = char_ranges[i + 1];
+              unsigned lim2 = char_ranges[i + 1] + 1;
 
-              for (; c1 <= c2; c1++)
+              for (; c1 < lim2; c1++)
                 {
                   int b = CHAR_TO_BYTE_SAFE (c1);
                   if (b >= 0)