diff --git a/src/fw/biostables.c b/src/fw/biostables.c
index 50a891b..450aca2 100644
--- a/src/fw/biostables.c
+++ b/src/fw/biostables.c
@@ -271,7 +271,7 @@
     if (SMBiosAddr)
         return;
     struct smbios_entry_point *p = pos;
-    if (memcmp(p->anchor_string, "_SM_", 4))
+    if (p->signature != SMBIOS_SIGNATURE)
         return;
     if (checksum(pos, 0x10) != 0)
         return;
diff --git a/src/fw/smbios.c b/src/fw/smbios.c
index dba0541..f3b5ad9 100644
--- a/src/fw/smbios.c
+++ b/src/fw/smbios.c
@@ -37,7 +37,7 @@
 
     struct smbios_entry_point ep;
     memset(&ep, 0, sizeof(ep));
-    memcpy(ep.anchor_string, "_SM_", 4);
+    ep.signature = SMBIOS_SIGNATURE;
     ep.length = 0x1f;
     ep.smbios_major_version = 2;
     ep.smbios_minor_version = 4;
diff --git a/src/std/smbios.h b/src/std/smbios.h
index 0513716..4ccf2ea 100644
--- a/src/std/smbios.h
+++ b/src/std/smbios.h
@@ -3,11 +3,13 @@
 
 #include "types.h" // u32
 
+#define SMBIOS_SIGNATURE 0x5f4d535f // "_SM_"
+
 /* SMBIOS entry point -- must be written to a 16-bit aligned address
    between 0xf0000 and 0xfffff.
  */
 struct smbios_entry_point {
-    char anchor_string[4];
+    u32 signature;
     u8 checksum;
     u8 length;
     u8 smbios_major_version;