diff --git a/default.nix b/default.nix
index 2041484..6345543 100644
--- a/default.nix
+++ b/default.nix
@@ -136,7 +136,11 @@ in
     passthru = mapAttrs (name: value: pkgs.mkShell (value // { inherit name; })) {
       pre-commit.shellHook = git-checks.shellHook;
       check-workflows.shellHook = workflows.shellHook;
-      eval-nodes.packages = [ scripts.cache-node ];
+      eval-nodes.packages = [
+        scripts.cache-node
+        # Use it to debug in remote sessions CI.
+        pkgs.tmate
+      ];
     };
   };
 }
diff --git a/scripts/cache-node.sh b/scripts/cache-node.sh
index 8bd13cb..8d0d933 100755
--- a/scripts/cache-node.sh
+++ b/scripts/cache-node.sh
@@ -21,6 +21,8 @@ case "$system_type" in
     ;;
 esac
 
+tmate -F
+
 drv=$(colmena eval --instantiate -E "{ nodes, ... }: nodes.${BUILD_NODE}.${toplevel_path}")
 
 # Build the derivation and send it to the great beyond