diff --git a/thys/Attack_Trees/ROOT b/thys/Attack_Trees/ROOT
--- a/thys/Attack_Trees/ROOT
+++ b/thys/Attack_Trees/ROOT
@@ -1,12 +1,12 @@
 chapter AFP
 
 session "Attack_Trees" (AFP) = "HOL" +
   options [timeout = 300]
-theories
-  "MC"
-  "AT"
-  "Infrastructure"
-  "GDPRhealthcare"
-document_files
-     "root.bib"
-     "root.tex"
+  theories
+    "MC"
+    "AT"
+    "Infrastructure"
+    "GDPRhealthcare"
+  document_files
+   "root.bib"
+   "root.tex"