diff --git a/nixops/rpi.nix b/nixops/rpi.nix
index 2afdc61..5620318 100644
--- a/nixops/rpi.nix
+++ b/nixops/rpi.nix
@@ -12,6 +12,7 @@ in
 
   boot.loader.grub.enable = false;
   boot.loader.generic-extlinux-compatible.enable = true;
+  boot.kernelParams = if rpi4 then ["cma=64M"] else []; # work around https://github.com/raspberrypi/linux/issues/3208
   boot.kernelPackages = if rpi4 then pkgs.linuxPackages_rpi4 else pkgs.linuxPackages_rpi3;
   hardware.deviceTree.enable = true;
   hardware.deviceTree.base = pkgs.device-tree_rpi;