1 files changed, 1 insertions, 1 deletions
diff --git a/lib/formdata.c b/lib/formdata.c
index 958e6cd2a..86c297745 100644
--- a/lib/formdata.c
+++ b/lib/formdata.c
@@ -1279,7 +1279,7 @@ static size_t readfromfile(struct Form *form, char *buffer, size_t size)
     /* this file hasn't yet been opened */
     form->fp = fopen(form->data->line, "rb"); /* b is for binary */
     if(!form->fp)
-      return -1; /* failure */
+      return (size_t)-1; /* failure */
   }
   nread = fread(buffer, 1, size, form->fp);