diff --git a/purism/librem/5r4/kernel/6.1.10.nix b/purism/librem/5r4/kernel/6.1.10.nix
deleted file mode 100644
index b68e0d0..0000000
--- a/purism/librem/5r4/kernel/6.1.10.nix
+++ /dev/null
@@ -1,14 +0,0 @@
-{ buildLinux, fetchFromGitLab, ... }@args:
-buildLinux (args // rec {
-  defconfig = "librem5_defconfig";
-  version = "6.1.10-librem5";
-  modDirVersion = version;
-  src = fetchFromGitLab {
-    domain = "source.puri.sm";
-    owner = "Librem5";
-    repo = "linux";
-    rev = "pureos/6.1.10pureos1";
-    hash = "sha256-Cc16vMUcJ/a2k3zMynqZ99t1LyTSs7EXKdNGF6OTS1s=";
-  };
-  kernelPatches = [ ];
-} // args.argsOverride or { })
diff --git a/purism/librem/5r4/kernel/6.4.5.nix b/purism/librem/5r4/kernel/6.4.5.nix
new file mode 100644
index 0000000..16a3497
--- /dev/null
+++ b/purism/librem/5r4/kernel/6.4.5.nix
@@ -0,0 +1,25 @@
+{ lib
+, buildLinux
+, fetchFromGitLab
+, ...
+} @ args:
+buildLinux (args
+  // rec {
+  defconfig = "librem5_defconfig";
+  version = "6.4.5-librem5";
+  modDirVersion = version;
+  src = fetchFromGitLab {
+    domain = "source.puri.sm";
+    owner = "Librem5";
+    repo = "linux";
+    rev = "pureos/6.4.5pureos1";
+    hash = "sha256-xg/qZ3Lig8oAAa3I+yn4tKPbftBy9Y6fnk8IvB+rm4E=";
+  };
+  kernelPatches = [ ];
+  structuredExtraConfig = with lib.kernel; {
+    # buildLinux overrides this and defaults to 32, so go back to the value defined librem5_defconfig
+    # this is required for millipixels to take photos, otherwise the VIDIOC_REQ_BUFS ioctl returns ENOMEM
+    CMA_SIZE_MBYTES = lib.mkForce (freeform "320");
+  };
+}
+  // args.argsOverride or { })
diff --git a/purism/librem/5r4/kernel/default.nix b/purism/librem/5r4/kernel/default.nix
index be57b35..19b8f3c 100644
--- a/purism/librem/5r4/kernel/default.nix
+++ b/purism/librem/5r4/kernel/default.nix
@@ -1,4 +1,4 @@
 final: prev: {
-  linuxPackages_librem5_6_1_10 = final.linuxPackagesFor (final.callPackage ./6.1.10.nix { });
-  linuxPackages_librem5 = final.linuxPackages_librem5_6_1_10;
+  linuxPackages_librem5_6_4_5 = final.linuxPackagesFor (final.callPackage ./6.4.5.nix { });
+  linuxPackages_librem5 = final.linuxPackages_librem5_6_4_5;
 }