diff --git a/src/util/psbt/map/global.rs b/src/util/psbt/map/global.rs
index 15e9c945..e834d181 100644
--- a/src/util/psbt/map/global.rs
+++ b/src/util/psbt/map/global.rs
@@ -32,6 +32,8 @@ const PSBT_GLOBAL_UNSIGNED_TX: u8 = 0x00;
 const PSBT_GLOBAL_XPUB: u8 = 0x01;
 /// Type: Version Number PSBT_GLOBAL_VERSION = 0xFB
 const PSBT_GLOBAL_VERSION: u8 = 0xFB;
+/// Type: Proprietary Use Type PSBT_GLOBAL_PROPRIETARY = 0xFC
+const PSBT_GLOBAL_PROPRIETARY: u8 = 0xFC;
 
 /// A key-value map for global data.
 #[derive(Clone, Debug, PartialEq)]
@@ -44,10 +46,12 @@ pub struct Global {
     /// A global map from extended public keys to the used key fingerprint and
     /// derivation path as defined by BIP 32
     pub xpub: BTreeMap<ExtendedPubKey, KeySource>,
+    /// Global proprietary key-value pairs.
+    pub proprietary: BTreeMap<raw::Key, Vec<u8>>,
     /// Unknown global key-value pairs.
     pub unknown: BTreeMap<raw::Key, Vec<u8>>,
 }
-serde_struct_impl!(Global, unsigned_tx, version, xpub, unknown);
+serde_struct_impl!(Global, unsigned_tx, version, xpub, proprietary, unknown);
 
 impl Global {
     /// Create a Global from an unsigned transaction, error if not unsigned
@@ -66,6 +70,7 @@ impl Global {
             unsigned_tx: tx,
             xpub: Default::default(),
             version: 0,
+            proprietary: Default::default(),
             unknown: Default::default(),
         })
     }
@@ -80,6 +85,10 @@ impl Map for Global {
 
         match raw_key.type_value {
             PSBT_GLOBAL_UNSIGNED_TX => return Err(Error::DuplicateKey(raw_key).into()),
+            PSBT_GLOBAL_PROPRIETARY => match self.proprietary.entry(raw_key) {
+                Entry::Vacant(empty_key) => {empty_key.insert(raw_value);},
+                Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
+            }
             _ => match self.unknown.entry(raw_key) {
                 Entry::Vacant(empty_key) => {empty_key.insert(raw_value);},
                 Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
@@ -135,6 +144,13 @@ impl Map for Global {
             });
         }
 
+        for (key, value) in self.proprietary.iter() {
+            rv.push(raw::Pair {
+                key: key.clone(),
+                value: value.clone(),
+            });
+        }
+
         for (key, value) in self.unknown.iter() {
             rv.push(raw::Pair {
                 key: key.clone(),
@@ -201,6 +217,7 @@ impl Map for Global {
             }
         }
 
+        self.proprietary.extend(other.proprietary);
         self.unknown.extend(other.unknown);
         Ok(())
     }
@@ -215,6 +232,7 @@ impl Decodable for Global {
         let mut version: Option<u32> = None;
         let mut unknowns: BTreeMap<raw::Key, Vec<u8>> = Default::default();
         let mut xpub_map: BTreeMap<ExtendedPubKey, (Fingerprint, DerivationPath)> = Default::default();
+        let mut proprietary: BTreeMap<raw::Key, Vec<u8>> = Default::default();
 
         loop {
             match raw::Pair::consensus_decode(&mut d) {
@@ -299,6 +317,10 @@ impl Decodable for Global {
                                 return Err(Error::InvalidKey(pair.key).into())
                             }
                         }
+                        PSBT_GLOBAL_PROPRIETARY => match proprietary.entry(pair.key) {
+                            Entry::Vacant(empty_key) => {empty_key.insert(pair.value);},
+                            Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
+                        }
                         _ => match unknowns.entry(pair.key) {
                             Entry::Vacant(empty_key) => {empty_key.insert(pair.value);},
                             Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
diff --git a/src/util/psbt/map/input.rs b/src/util/psbt/map/input.rs
index ef8c3fc6..17f7503a 100644
--- a/src/util/psbt/map/input.rs
+++ b/src/util/psbt/map/input.rs
@@ -52,6 +52,8 @@ const PSBT_IN_SHA256: u8 = 0x0b;
 const PSBT_IN_HASH160: u8 = 0x0c;
 /// Type: HASH256 preimage PSBT_IN_HASH256 = 0x0d
 const PSBT_IN_HASH256: u8 = 0x0d;
+/// Type: Proprietary Use Type PSBT_IN_PROPRIETARY = 0xFC
+const PSBT_IN_PROPRIETARY: u8 = 0xFC;
 
 /// A key-value map for an input of the corresponding index in the unsigned
 /// transaction.
@@ -93,6 +95,8 @@ pub struct Input {
     pub hash160_preimages: BTreeMap<hash160::Hash, Vec<u8>>,
     /// HAS256 hash to preimage map
     pub hash256_preimages: BTreeMap<sha256d::Hash, Vec<u8>>,
+    /// Proprietary key-value pairs for this input.
+    pub proprietary: BTreeMap<raw::Key, Vec<u8>>,
     /// Unknown key-value pairs for this input.
     pub unknown: BTreeMap<raw::Key, Vec<u8>>,
 }
@@ -101,7 +105,7 @@ serde_struct_impl!(
     sighash_type, redeem_script, witness_script, bip32_derivation,
     final_script_sig, final_script_witness,
     ripemd160_preimages, sha256_preimages, hash160_preimages, hash256_preimages,
-    unknown
+    proprietary, unknown
 );
 
 impl Map for Input {
@@ -169,6 +173,10 @@ impl Map for Input {
             PSBT_IN_HASH256 => {
                 psbt_insert_hash_pair(&mut self.hash256_preimages, raw_key, raw_value, error::PsbtHash::Hash256)?;
             }
+            PSBT_IN_PROPRIETARY => match self.proprietary.entry(raw_key) {
+                ::std::collections::btree_map::Entry::Vacant(empty_key) => {empty_key.insert(raw_value);},
+                ::std::collections::btree_map::Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
+            }
             _ => match self.unknown.entry(raw_key) {
                 ::std::collections::btree_map::Entry::Vacant(empty_key) => {
                     empty_key.insert(raw_value);
@@ -237,6 +245,13 @@ impl Map for Input {
             rv.push(self.hash256_preimages as <PSBT_IN_HASH256, sha256d::Hash>|<Vec<u8>>)
         }
 
+        for (key, value) in self.proprietary.iter() {
+            rv.push(raw::Pair {
+                key: key.clone(),
+                value: value.clone(),
+            });
+        }
+
         for (key, value) in self.unknown.iter() {
             rv.push(raw::Pair {
                 key: key.clone(),
@@ -261,6 +276,7 @@ impl Map for Input {
         self.sha256_preimages.extend(other.sha256_preimages);
         self.hash160_preimages.extend(other.hash160_preimages);
         self.hash256_preimages.extend(other.hash256_preimages);
+        self.proprietary.extend(other.proprietary);
         self.unknown.extend(other.unknown);
 
         merge!(redeem_script, self, other);
diff --git a/src/util/psbt/map/output.rs b/src/util/psbt/map/output.rs
index 7be5a37c..3e25d300 100644
--- a/src/util/psbt/map/output.rs
+++ b/src/util/psbt/map/output.rs
@@ -30,6 +30,8 @@ const PSBT_OUT_REDEEM_SCRIPT: u8 = 0x00;
 const PSBT_OUT_WITNESS_SCRIPT: u8 = 0x01;
 /// Type: BIP 32 Derivation Path PSBT_OUT_BIP32_DERIVATION = 0x02
 const PSBT_OUT_BIP32_DERIVATION: u8 = 0x02;
+/// Type: Proprietary Use Type PSBT_IN_PROPRIETARY = 0xFC
+const PSBT_OUT_PROPRIETARY: u8 = 0xFC;
 
 /// A key-value map for an output of the corresponding index in the unsigned
 /// transaction.
@@ -42,11 +44,13 @@ pub struct Output {
     /// A map from public keys needed to spend this output to their
     /// corresponding master key fingerprints and derivation paths.
     pub bip32_derivation: BTreeMap<PublicKey, KeySource>,
+    /// Proprietary key-value pairs for this output.
+    pub proprietary: BTreeMap<raw::Key, Vec<u8>>,
     /// Unknown key-value pairs for this output.
     pub unknown: BTreeMap<raw::Key, Vec<u8>>,
 }
 serde_struct_impl!(
-    Output, redeem_script, witness_script, bip32_derivation, unknown
+    Output, redeem_script, witness_script, bip32_derivation, proprietary, unknown
 );
 
 impl Map for Output {
@@ -72,6 +76,10 @@ impl Map for Output {
                     self.bip32_derivation <= <raw_key: PublicKey>|<raw_value: KeySource>
                 }
             }
+            PSBT_OUT_PROPRIETARY => match self.proprietary.entry(raw_key) {
+                Entry::Vacant(empty_key) => {empty_key.insert(raw_value);},
+                Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
+            }
             _ => match self.unknown.entry(raw_key) {
                     Entry::Vacant(empty_key) => {empty_key.insert(raw_value);},
                     Entry::Occupied(k) => return Err(Error::DuplicateKey(k.key().clone()).into()),
@@ -96,6 +104,13 @@ impl Map for Output {
             rv.push(self.bip32_derivation as <PSBT_OUT_BIP32_DERIVATION, PublicKey>|<KeySource>)
         }
 
+        for (key, value) in self.proprietary.iter() {
+            rv.push(raw::Pair {
+                key: key.clone(),
+                value: value.clone(),
+            });
+        }
+
         for (key, value) in self.unknown.iter() {
             rv.push(raw::Pair {
                 key: key.clone(),
@@ -108,6 +123,7 @@ impl Map for Output {
 
     fn merge(&mut self, other: Self) -> Result<(), psbt::Error> {
         self.bip32_derivation.extend(other.bip32_derivation);
+        self.proprietary.extend(other.proprietary);
         self.unknown.extend(other.unknown);
 
         merge!(redeem_script, self, other);
diff --git a/src/util/psbt/mod.rs b/src/util/psbt/mod.rs
index f3384d4a..caaae382 100644
--- a/src/util/psbt/mod.rs
+++ b/src/util/psbt/mod.rs
@@ -194,6 +194,7 @@ mod tests {
                 },
                 xpub: Default::default(),
                 version: 0,
+                proprietary: BTreeMap::new(),
                 unknown: BTreeMap::new(),
             },
             inputs: vec![],
@@ -283,6 +284,7 @@ mod tests {
             },
             xpub: Default::default(),
             version: 0,
+            proprietary: Default::default(),
             unknown: Default::default(),
         };
 
@@ -387,6 +389,7 @@ mod tests {
                     },
                     xpub: Default::default(),
                     version: 0,
+                    proprietary: BTreeMap::new(),
                     unknown: BTreeMap::new(),
                 },
                 inputs: vec![Input {
@@ -612,6 +615,7 @@ mod tests {
                 },
                 version: 0,
                 xpub: Default::default(),
+                proprietary: Default::default(),
                 unknown: BTreeMap::new(),
             },
             inputs: vec![Input {