diff --git a/bdk-ffi/src/bitcoin.rs b/bdk-ffi/src/bitcoin.rs
index 038ec19..98953e8 100644
--- a/bdk-ffi/src/bitcoin.rs
+++ b/bdk-ffi/src/bitcoin.rs
@@ -124,7 +124,7 @@ impl Transaction {
     }
 
     pub fn weight(&self) -> u64 {
-        self.inner.weight().to_wu()
+        self.0.weight().to_wu()
     }
 
     pub fn total_size(&self) -> u64 {
diff --git a/bdk-ffi/src/keys.rs b/bdk-ffi/src/keys.rs
index d4506f9..a0daa9e 100644
--- a/bdk-ffi/src/keys.rs
+++ b/bdk-ffi/src/keys.rs
@@ -113,7 +113,7 @@ impl DescriptorSecretKey {
         }
     }
 
-    pub(crate) fn extend(&self, path: &DerivationPath) -> Result<Arc<Self>, Alpha3Error> {
+    pub(crate) fn extend(&self, path: &DerivationPath) -> Result<Arc<Self>, DescriptorKeyError> {
         let descriptor_secret_key = &self.0;
         let path = path.inner_mutex.lock().unwrap().deref().clone();
         match descriptor_secret_key {
@@ -198,7 +198,7 @@ impl DescriptorPublicKey {
         }
     }
 
-    pub(crate) fn extend(&self, path: &DerivationPath) -> Result<Arc<Self>, Alpha3Error> {
+    pub(crate) fn extend(&self, path: &DerivationPath) -> Result<Arc<Self>, DescriptorKeyError> {
         let descriptor_public_key = &self.0;
         let path = path.inner_mutex.lock().unwrap().deref().clone();
         match descriptor_public_key {