diff --git a/pine64/star64/README.md b/pine64/star64/README.md
index 08b6d36..f74da94 100644
--- a/pine64/star64/README.md
+++ b/pine64/star64/README.md
@@ -83,6 +83,24 @@ hardware.deviceTree.overlays = [{
 
 # Updating the bootloader
 
+## eMMC
+
+Install the firmware update script
+
+``` nix
+environment.systemPackages = [
+  (pkgs.callPackage
+    "${nixos-hardware}/pine64/star64/firmware.nix"
+    { }).updater-mmc
+];
+```
+
+Then run as root
+
+``` sh
+star64-firmware-update-mmc
+```
+
 ## SD-Card
 
 Install the firmware update script
diff --git a/pine64/star64/firmware.nix b/pine64/star64/firmware.nix
index b1b76c8..c300de4 100644
--- a/pine64/star64/firmware.nix
+++ b/pine64/star64/firmware.nix
@@ -67,12 +67,20 @@ in rec {
       flashcp -v ${uboot-fit-image}/share/pine64-star64/star64_fw_payload.img /dev/mtd1
     '';
   };
-  updater-sd = writeShellApplication {
-    name = "star64-firmware-update-sd";
+  updater-mmc = writeShellApplication {
+    name = "star64-firmware-update-mmc";
     runtimeInputs = [ ];
     text = ''
       dd if=${spl}/share/pine64-star64/spl.bin of=/dev/mmcblk0p1 conv=fsync
       dd if=${uboot-fit-image}/share/pine64-star64/star64_fw_payload.img of=/dev/mmcblk0p2 conv=fsync
     '';
   };
+  updater-sd = writeShellApplication {
+    name = "star64-firmware-update-sd";
+    runtimeInputs = [ ];
+    text = ''
+      dd if=${spl}/share/pine64-star64/spl.bin of=/dev/mmcblk1p1 conv=fsync
+      dd if=${uboot-fit-image}/share/pine64-star64/star64_fw_payload.img of=/dev/mmcblk1p2 conv=fsync
+    '';
+  };
 }