diff --git a/hosts/idols-ai/disko-fs.nix b/hosts/idols-ai/disko-fs.nix
index 50514bc2..df914069 100644
--- a/hosts/idols-ai/disko-fs.nix
+++ b/hosts/idols-ai/disko-fs.nix
@@ -112,10 +112,12 @@
                       "compress-force=zstd:1"
                     ];
                   };
-                  # Swap subvolume read-only; disko creates swapfile and adds swapDevices
+                  # Swap subvolume read-only; disko creates swapfile and adds swapDevices.
+                  # The swapfile is preallocated and never compressed (btrfs swapfile
+                  # requirements), so it consumes its full size on the pool.
                   "@swap" = {
                     mountpoint = "/swap";
-                    swap.swapfile.size = "96G";
+                    swap.swapfile.size = "32G";
                   };
                 };
               };
diff --git a/hosts/idols-aquamarine/README.md b/hosts/idols-aquamarine/README.md
index 53616bdf..7448743d 100644
--- a/hosts/idols-aquamarine/README.md
+++ b/hosts/idols-aquamarine/README.md
@@ -39,7 +39,7 @@ defect that is, the supported ROCm versions, and the inference notes.
 ## Disk layout
 
 Declarative via [disko-fs.nix](./disko-fs.nix): ESP + LUKS (`aqua-luks`) + btrfs subvolumes (`@nix`,
-`@persistent`, `@snapshots`, `@tmp`, `@swap` with a 96G swapfile), ephemeral tmpfs root, state under
+`@persistent`, `@snapshots`, `@tmp`, `@swap` with a 32G swapfile), ephemeral tmpfs root, state under
 `/persistent` via [preservation.nix](./preservation.nix). Secure Boot via lanzaboote
 ([secureboot.nix](./secureboot.nix)).
 
diff --git a/hosts/idols-aquamarine/disko-fs.nix b/hosts/idols-aquamarine/disko-fs.nix
index 34ab95fc..051cf4fc 100644
--- a/hosts/idols-aquamarine/disko-fs.nix
+++ b/hosts/idols-aquamarine/disko-fs.nix
@@ -116,10 +116,12 @@
                       "compress-force=zstd:1"
                     ];
                   };
-                  # disko creates the 96G swapfile on this subvolume and adds swapDevices
+                  # disko creates the 32G swapfile on this subvolume and adds swapDevices.
+                  # It is preallocated and never compressed (btrfs swapfile requirements),
+                  # so it consumes its full size on the pool.
                   "@swap" = {
                     mountpoint = "/swap";
-                    swap.swapfile.size = "96G";
+                    swap.swapfile.size = "32G";
                   };
                 };
               };