1 files changed, 1 insertions, 1 deletions

diff --git a/src/category.c b/src/category.c
index 851ae1a4c24..a4610e4d358 100644
--- a/src/category.c
+++ b/src/category.c
@@ -96,7 +96,7 @@ those categories.  */)
   (Lisp_Object categories)
 {
   Lisp_Object val;
-  int len;
+  ptrdiff_t len;
 
   CHECK_STRING (categories);
   val = MAKE_CATEGORY_SET;