Index: head/lib/libc/tests/sys/sendfile_test.c
===================================================================
--- head/lib/libc/tests/sys/sendfile_test.c
+++ head/lib/libc/tests/sys/sendfile_test.c
@@ -289,8 +289,8 @@
 	length = (nbytes == 0) ? (size_t)(src_file_size - offset) : nbytes;
 
 	ATF_REQUIRE_EQ_MSG(dest_file_size, length,
-	    "number of bytes written out to %s (%ju) doesn't match the "
-	    "expected number of bytes (%ju)", dest_filename, dest_file_size,
+	    "number of bytes written out to %s (%zu) doesn't match the "
+	    "expected number of bytes (%zu)", dest_filename, dest_file_size,
 	    length);
 
 	ATF_REQUIRE_EQ_MSG(0, lseek(src_fd, offset, SEEK_SET),