diff --git a/hosts/backwards/modules/syncthing/default.nix b/hosts/backwards/modules/syncthing/default.nix
index bda67a9..88433b9 100644
--- a/hosts/backwards/modules/syncthing/default.nix
+++ b/hosts/backwards/modules/syncthing/default.nix
@@ -54,6 +54,17 @@
           };
         };
 
+        books = {
+          path = "/home/alex/sync/books";
+          devices = [ "pinwheel" ];
+          versioning = {
+            type = "staggered";
+            params = {
+              maxAge = "2592000"; # 30 days
+            };
+          };
+        };
+
         "phone-gps" = {
           path = "/home/alex/sync/phone-gps";
           devices = [ "phone" ];
diff --git a/hosts/pinwheel/modules/syncthing/default.nix b/hosts/pinwheel/modules/syncthing/default.nix
index fe390cd..020e21c 100644
--- a/hosts/pinwheel/modules/syncthing/default.nix
+++ b/hosts/pinwheel/modules/syncthing/default.nix
@@ -55,7 +55,7 @@
 
         books = {
           path = "/home/alex/sync/books";
-          devices = [ "sombrero" ];
+          devices = [ "sombrero" "backwards" ];
           versioning = {
             type = "staggered";
             params = {