diff --git a/tool/src/main.rs b/tool/src/main.rs
index 5fd53c6..480c442 100644
--- a/tool/src/main.rs
+++ b/tool/src/main.rs
@@ -93,7 +93,7 @@ unsafe fn flash_read<S: Spi>(spi: &mut SpiRom<S, StdTimeout>, rom: &mut [u8], se
 
 unsafe fn flash_inner(ec: &mut Ec<StdTimeout>, firmware: &Firmware, target: SpiTarget, scratch: bool) -> Result<(), Error> {
     let rom_size = 128 * 1024;
-    let sector_size = 4096;
+    let sector_size = 1024;
 
     let mut new_rom = firmware.data.to_vec();
     while new_rom.len() < rom_size {
diff --git a/tool/src/spi.rs b/tool/src/spi.rs
index 1b4d71f..99c336c 100644
--- a/tool/src/spi.rs
+++ b/tool/src/spi.rs
@@ -90,7 +90,7 @@ impl<'a, S: Spi, T: Timeout> SpiRom<'a, S, T> {
 
         self.spi.reset()?;
         self.spi.write(&[
-            0x20,
+            0xD7,
             (address >> 16) as u8,
             (address >> 8) as u8,
             address as u8,