diff --git a/Book.Rproj b/Book.Rproj
index e4c1c67d2..37a47739a 100644
--- a/Book.Rproj
+++ b/Book.Rproj
@@ -1,4 +1,5 @@
 Version: 1.0
+ProjectId: b4fd2ecf-016e-4fc2-bdcd-ba2ad573535c
 
 RestoreWorkspace: Default
 SaveWorkspace: Default