diff --git a/src/eth/rx.rs b/src/eth/rx.rs
index c56ff191..34a919e9 100644
--- a/src/eth/rx.rs
+++ b/src/eth/rx.rs
@@ -11,7 +11,7 @@ pub enum Error {
 }
 
 /// Descriptor entry
-#[repr(C)]
+#[repr(C, align(0x08))]
 pub struct DescEntry {
     word0: DescWord0,
     word1: DescWord1,
diff --git a/src/eth/tx.rs b/src/eth/tx.rs
index 40073638..a9b0d198 100644
--- a/src/eth/tx.rs
+++ b/src/eth/tx.rs
@@ -4,6 +4,7 @@ use crate::println;
 use super::{MTU, regs};
 
 /// Descriptor entry
+#[repr(C, align(0x08))]
 pub struct DescEntry {
     word0: DescWord0,
     word1: DescWord1,