diff --git a/crates/fbuild-deploy/src/rp2040.rs b/crates/fbuild-deploy/src/rp2040.rs
index 30f4145e9..c99a36463 100644
--- a/crates/fbuild-deploy/src/rp2040.rs
+++ b/crates/fbuild-deploy/src/rp2040.rs
@@ -23,7 +23,7 @@ use target::{
     resolve_requested_runtime_target, select_cdc_candidate, serial_selector,
 };
 
-const UF2_MAGIC_START0: u32 = 0x0A32_4555;
+const UF2_MAGIC_START0: u32 = 0x0A32_4655;
 const UF2_MAGIC_START1: u32 = 0x9E5D_5157;
 const UF2_MAGIC_END: u32 = 0x0AB1_6F30;
 const UF2_FLAG_FAMILY_ID_PRESENT: u32 = 0x0000_2000;
@@ -758,6 +758,13 @@ mod tests {
         );
     }
 
+    #[test]
+    fn uf2_magic_matches_the_published_byte_sequence() {
+        assert_eq!(UF2_MAGIC_START0.to_le_bytes(), [0x55, 0x46, 0x32, 0x0A]);
+        assert_eq!(UF2_MAGIC_START1.to_le_bytes(), [0x57, 0x51, 0x5D, 0x9E]);
+        assert_eq!(UF2_MAGIC_END.to_le_bytes(), [0x30, 0x6F, 0xB1, 0x0A]);
+    }
+
     #[test]
     fn full_image_boot2_uses_xip_address() {
         // Prefix emitted by the RP2040 second-stage bootloader in FastLED's