diff --git a/alioth/src/firmware/firmware.rs b/alioth/src/firmware/firmware.rs
index 10c06a67..6757a727 100644
--- a/alioth/src/firmware/firmware.rs
+++ b/alioth/src/firmware/firmware.rs
@@ -26,6 +26,7 @@ use snafu::Snafu;
 
 use crate::errors::{DebugTrace, trace_error};
 
+use self::ovmf::x86_64::sev::SEV_SIGNATURE;
 use self::ovmf::x86_64::tdx::{TDVF_SIGNATURE, TDVF_VERSION};
 
 #[trace_error]
@@ -36,6 +37,8 @@ pub enum Error {
     MissingMetadata { name: &'static str },
     #[snafu(display("Firmware missing TDVF signature {TDVF_SIGNATURE:08x}, got {got:08x}"))]
     MissingTdvfSignature { got: u32 },
+    #[snafu(display("Firmware missing AMD-SEV signature {SEV_SIGNATURE:08x}, got {got:08x}"))]
+    MissingAmdSevSignature { got: u32 },
     #[snafu(display("Firmware missing TDVF version {TDVF_VERSION}, got {got}"))]
     MissingTdvfVersion { got: u32 },
     #[snafu(display("Invalid firmware data layout"))]
diff --git a/alioth/src/firmware/ovmf/ovmf_x86_64/sev.rs b/alioth/src/firmware/ovmf/ovmf_x86_64/sev.rs
index a039bb86..fa5ed602 100644
--- a/alioth/src/firmware/ovmf/ovmf_x86_64/sev.rs
+++ b/alioth/src/firmware/ovmf/ovmf_x86_64/sev.rs
@@ -25,6 +25,7 @@ pub const GUID_SEV_ES_RESET_BLOCK: [u8; GUID_SIZE] = [
 pub const GUID_SEV_METADATA: [u8; GUID_SIZE] = [
     0x66, 0x65, 0x88, 0xdc, 0x4a, 0x98, 0x98, 0x47, 0xA7, 0x5e, 0x55, 0x85, 0xa7, 0xbf, 0x67, 0xcc,
 ];
+pub const SEV_SIGNATURE: u32 = u32::from_le_bytes(*b"ASEV");
 
 #[derive(Debug, KnownLayout, Immutable, FromBytes, IntoBytes)]
 #[repr(C)]
@@ -102,6 +103,12 @@ pub fn parse_desc(data: &[u8]) -> Result<&[SevMetadataDesc]> {
     let Ok((metadata, remain)) = SevMetaData::ref_from_prefix(&data[offset..]) else {
         return error::InvalidLayout.fail();
     };
+    if metadata.signature != SEV_SIGNATURE {
+        return error::MissingAmdSevSignature {
+            got: metadata.signature,
+        }
+        .fail();
+    };
     let Ok((entries, _)) =
         <[SevMetadataDesc]>::ref_from_prefix_with_elems(remain, metadata.num_desc as usize)
     else {