diff --git a/Featherweight_OCL/ROOT b/Featherweight_OCL/ROOT
index 1fce9c4..3ef4b7d 100644
--- a/Featherweight_OCL/ROOT
+++ b/Featherweight_OCL/ROOT
@@ -1,6 +1,6 @@
 chapter AFP
 
-session Featherweight_OCL-devel (AFP) = HOL +
+session "Featherweight_OCL-devel" (AFP) = HOL +
   description {* Featherweight-OCL *}
   options [document_variants = "annex-a=annexa,-theory,-afp,-proof,-ML:document=afp,-annexa:outline=-annexa,afp,/proof,/ML",
            show_question_marks = false, timeout = 600]