diff --git a/src/coredump/coredump.c b/src/coredump/coredump.c
index c9747416ad..994d968d87 100644
--- a/src/coredump/coredump.c
+++ b/src/coredump/coredump.c
@@ -512,8 +512,8 @@ static int save_external_coredump(
 
         if (truncated)
                 log_struct(LOG_INFO,
-                           LOG_MESSAGE("Core file was truncated to %zu bytes.", max_size),
-                           "SIZE_LIMIT=%zu", max_size,
+                           LOG_MESSAGE("Core file was truncated to %"PRIu64" bytes.", max_size),
+                           "SIZE_LIMIT=%"PRIu64, max_size,
                            "MESSAGE_ID=" SD_MESSAGE_TRUNCATED_CORE_STR);
 
         r = fix_permissions(fd, tmp, fn, context, uid);