diff --git a/tools/atree/files.cpp b/tools/atree/files.cpp
index d5c8a97..b90f8b3 100644
--- a/tools/atree/files.cpp
+++ b/tools/atree/files.cpp
@@ -81,7 +81,7 @@
                     state = TEXT;
                     break;
                 }
-                // otherwise fall-through to TEXT case
+                [[fallthrough]];
             case TEXT:
                 if (state != IN_QUOTE && isspace(*p)) {
                     if (q != p) {