diff --git a/src/lib.rs b/src/lib.rs
index 7e8e18e..b240f95 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -433,7 +433,7 @@
 
 /// `FFA_FEATURES` specific success argument structure. This type needs further specialization based
 /// on 'FF-A function ID or Feature ID' field of the preceeding `FFA_FEATURES` request.
-#[derive(Debug, Eq, PartialEq, Clone, Copy)]
+#[derive(Debug, Eq, Default, PartialEq, Clone, Copy)]
 pub struct SuccessArgsFeatures {
     pub properties: [u32; 2],
 }
@@ -541,7 +541,7 @@
 }
 
 /// Flags field of the FFA_MSG_SEND2 interface.
-#[derive(Debug, Eq, PartialEq, Clone, Copy)]
+#[derive(Debug, Eq, Default, PartialEq, Clone, Copy)]
 pub struct MsgSend2Flags {
     pub delay_schedule_receiver: bool,
 }
@@ -697,7 +697,7 @@
 #[derive(Debug, Eq, PartialEq, Clone, Copy)]
 pub struct DirectMsg2Args(pub [u64; 14]);
 
-#[derive(Debug, Eq, PartialEq, Clone, Copy)]
+#[derive(Debug, Default, Eq, PartialEq, Clone, Copy)]
 pub struct MsgWaitFlags {
     pub retain_rx_buffer: bool,
 }
diff --git a/src/memory_management.rs b/src/memory_management.rs
index 3203c15..8b39824 100644
--- a/src/memory_management.rs
+++ b/src/memory_management.rs
@@ -848,7 +848,7 @@
 }
 
 /// Flags field of the FFA_MEM_RECLAIM interface.
-#[derive(Debug, Eq, PartialEq, Clone, Copy)]
+#[derive(Debug, Default, Eq, PartialEq, Clone, Copy)]
 pub struct MemReclaimFlags {
     pub zero_memory: bool,
     pub time_slicing: bool,
@@ -889,6 +889,7 @@
 }
 
 /// Success argument structure for `FFA_MEM_DONATE`, `FFA_MEM_LEND` and `FFA_MEM_SHARE`.
+#[derive(Debug, Eq, PartialEq, Clone, Copy)]
 pub struct SuccessArgsMemOp {
     pub handle: Handle,
 }
@@ -993,6 +994,7 @@
 }
 
 /// Success argument structure for `FFA_MEM_PERM_GET`.
+#[derive(Debug, Eq, PartialEq, Clone, Copy)]
 pub struct SuccessArgsMemPermGet {
     pub perm: MemPermissionsGetSet,
     pub page_cnt: u32,