diff --git a/vcs-svn/sliding_window.c b/vcs-svn/sliding_window.c
index c6c2effd30..ec2707c9c4 100644
--- a/vcs-svn/sliding_window.c
+++ b/vcs-svn/sliding_window.c
@@ -31,15 +31,15 @@ static int read_to_fill_or_whine(struct line_buffer *file,
 	return 0;
 }
 
-static int check_offset_overflow(off_t offset, size_t len)
+static int check_offset_overflow(off_t offset, uintmax_t len)
 {
 	if (len > maximum_signed_value_of_type(off_t))
 		return error("unrepresentable length in delta: "
-				"%"PRIuMAX" > OFF_MAX", (uintmax_t) len);
+				"%"PRIuMAX" > OFF_MAX", len);
 	if (signed_add_overflows(offset, (off_t) len))
 		return error("unrepresentable offset in delta: "
 				"%"PRIuMAX" + %"PRIuMAX" > OFF_MAX",
-				(uintmax_t) offset, (uintmax_t) len);
+				(uintmax_t) offset, len);
 	return 0;
 }