diff --git a/librustzcash/src/rustzcash.rs b/librustzcash/src/rustzcash.rs
index 0fad706..99c3187 100644
--- a/librustzcash/src/rustzcash.rs
+++ b/librustzcash/src/rustzcash.rs
@@ -705,7 +705,7 @@ pub extern "system" fn librustzcash_sapling_final_check(
     binding_sig: *const [c_uchar; 64],
     sighash_value: *const [c_uchar; 32],
 ) -> bool {
-    let value_balance = match Amount::from_i64(value_balance, true) {
+    let value_balance = match Amount::from_i64(value_balance) {
         Ok(vb) => vb,
         Err(()) => return false,
     };
@@ -1028,7 +1028,7 @@ pub extern "system" fn librustzcash_sapling_binding_sig(
     sighash: *const [c_uchar; 32],
     result: *mut [c_uchar; 64],
 ) -> bool {
-    let value_balance = match Amount::from_i64(value_balance, true) {
+    let value_balance = match Amount::from_i64(value_balance) {
         Ok(vb) => vb,
         Err(()) => return false,
     };
diff --git a/zcash_primitives/src/transaction/builder.rs b/zcash_primitives/src/transaction/builder.rs
index 36490e4..ba07f34 100644
--- a/zcash_primitives/src/transaction/builder.rs
+++ b/zcash_primitives/src/transaction/builder.rs
@@ -564,7 +564,7 @@ mod tests {
         let to = extfvk.default_address().unwrap().1;
 
         let mut builder = Builder::new(0);
-        match builder.add_sapling_output(ovk, to, Amount::from_i64(-1, true).unwrap(), None) {
+        match builder.add_sapling_output(ovk, to, Amount::from_i64(-1).unwrap(), None) {
             Err(e) => assert_eq!(e.kind(), &ErrorKind::InvalidAmount),
             Ok(_) => panic!("Should have failed"),
         }
@@ -575,7 +575,7 @@ mod tests {
         let mut builder = Builder::new(0);
         match builder.add_transparent_output(
             &TransparentAddress::PublicKey([0; 20]),
-            Amount::from_i64(-1, true).unwrap(),
+            Amount::from_i64(-1).unwrap(),
         ) {
             Err(e) => assert_eq!(e.kind(), &ErrorKind::InvalidAmount),
             Ok(_) => panic!("Should have failed"),
@@ -596,7 +596,7 @@ mod tests {
             match builder.build(1, MockTxProver) {
                 Err(e) => assert_eq!(
                     e.kind(),
-                    &ErrorKind::ChangeIsNegative(Amount::from_i64(-10000, true).unwrap())
+                    &ErrorKind::ChangeIsNegative(Amount::from_i64(-10000).unwrap())
                 ),
                 Ok(_) => panic!("Should have failed"),
             }
@@ -621,7 +621,7 @@ mod tests {
             match builder.build(1, MockTxProver) {
                 Err(e) => assert_eq!(
                     e.kind(),
-                    &ErrorKind::ChangeIsNegative(Amount::from_i64(-60000, true).unwrap())
+                    &ErrorKind::ChangeIsNegative(Amount::from_i64(-60000).unwrap())
                 ),
                 Ok(_) => panic!("Should have failed"),
             }
@@ -640,7 +640,7 @@ mod tests {
             match builder.build(1, MockTxProver) {
                 Err(e) => assert_eq!(
                     e.kind(),
-                    &ErrorKind::ChangeIsNegative(Amount::from_i64(-60000, true).unwrap())
+                    &ErrorKind::ChangeIsNegative(Amount::from_i64(-60000).unwrap())
                 ),
                 Ok(_) => panic!("Should have failed"),
             }
@@ -683,7 +683,7 @@ mod tests {
             match builder.build(1, MockTxProver) {
                 Err(e) => assert_eq!(
                     e.kind(),
-                    &ErrorKind::ChangeIsNegative(Amount::from_i64(-1, true).unwrap())
+                    &ErrorKind::ChangeIsNegative(Amount::from_i64(-1).unwrap())
                 ),
                 Ok(_) => panic!("Should have failed"),
             }
diff --git a/zcash_primitives/src/transaction/components.rs b/zcash_primitives/src/transaction/components.rs
index c7dcebd..d50b4fb 100644
--- a/zcash_primitives/src/transaction/components.rs
+++ b/zcash_primitives/src/transaction/components.rs
@@ -79,7 +79,7 @@ impl TxOut {
         let value = {
             let mut tmp = [0; 8];
             reader.read_exact(&mut tmp)?;
-            Amount::from_i64_le_bytes(tmp, false)
+            Amount::from_nonnegative_i64_le_bytes(tmp)
         }
         .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "value out of range"))?;
         let script_pubkey = Script::read(&mut reader)?;
diff --git a/zcash_primitives/src/transaction/components/amount.rs b/zcash_primitives/src/transaction/components/amount.rs
index dca7056..d244876 100644
--- a/zcash_primitives/src/transaction/components/amount.rs
+++ b/zcash_primitives/src/transaction/components/amount.rs
@@ -18,10 +18,19 @@ impl Amount {
     /// Creates an Amount from an i64.
     ///
     /// Returns an error if the amount is out of range.
-    pub fn from_i64(amount: i64, allow_negative: bool) -> Result<Self, ()> {
-        if 0 <= amount && amount <= MAX_MONEY {
+    pub fn from_i64(amount: i64) -> Result<Self, ()> {
+        if -MAX_MONEY <= amount && amount <= MAX_MONEY {
             Ok(Amount(amount))
-        } else if allow_negative && -MAX_MONEY <= amount && amount < 0 {
+        } else {
+            Err(())
+        }
+    }
+
+    /// Creates a non-negative Amount from an i64.
+    ///
+    /// Returns an error if the amount is out of range.
+    pub fn from_nonnegative_i64(amount: i64) -> Result<Self, ()> {
+        if 0 <= amount && amount <= MAX_MONEY {
             Ok(Amount(amount))
         } else {
             Err(())
@@ -42,9 +51,17 @@ impl Amount {
     /// Reads an Amount from a signed 64-bit little-endian integer.
     ///
     /// Returns an error if the amount is out of range.
-    pub fn from_i64_le_bytes(bytes: [u8; 8], allow_negative: bool) -> Result<Self, ()> {
+    pub fn from_i64_le_bytes(bytes: [u8; 8]) -> Result<Self, ()> {
         let amount = i64::from_le_bytes(bytes);
-        Amount::from_i64(amount, allow_negative)
+        Amount::from_i64(amount)
+    }
+
+    /// Reads a non-negative Amount from a signed 64-bit little-endian integer.
+    ///
+    /// Returns an error if the amount is out of range.
+    pub fn from_nonnegative_i64_le_bytes(bytes: [u8; 8]) -> Result<Self, ()> {
+        let amount = i64::from_le_bytes(bytes);
+        Amount::from_nonnegative_i64(amount)
     }
 
     /// Reads an Amount from an unsigned 64-bit little-endian integer.
@@ -128,19 +145,16 @@ mod tests {
         let zero = b"\x00\x00\x00\x00\x00\x00\x00\x00";
         assert_eq!(Amount::from_u64_le_bytes(zero.clone()).unwrap(), Amount(0));
         assert_eq!(
-            Amount::from_i64_le_bytes(zero.clone(), false).unwrap(),
-            Amount(0)
-        );
-        assert_eq!(
-            Amount::from_i64_le_bytes(zero.clone(), true).unwrap(),
+            Amount::from_nonnegative_i64_le_bytes(zero.clone()).unwrap(),
             Amount(0)
         );
+        assert_eq!(Amount::from_i64_le_bytes(zero.clone()).unwrap(), Amount(0));
 
         let neg_one = b"\xff\xff\xff\xff\xff\xff\xff\xff";
         assert!(Amount::from_u64_le_bytes(neg_one.clone()).is_err());
-        assert!(Amount::from_i64_le_bytes(neg_one.clone(), false).is_err());
+        assert!(Amount::from_nonnegative_i64_le_bytes(neg_one.clone()).is_err());
         assert_eq!(
-            Amount::from_i64_le_bytes(neg_one.clone(), true).unwrap(),
+            Amount::from_i64_le_bytes(neg_one.clone()).unwrap(),
             Amount(-1)
         );
 
@@ -150,30 +164,30 @@ mod tests {
             Amount(MAX_MONEY)
         );
         assert_eq!(
-            Amount::from_i64_le_bytes(max_money.clone(), false).unwrap(),
+            Amount::from_nonnegative_i64_le_bytes(max_money.clone()).unwrap(),
             Amount(MAX_MONEY)
         );
         assert_eq!(
-            Amount::from_i64_le_bytes(max_money.clone(), true).unwrap(),
+            Amount::from_i64_le_bytes(max_money.clone()).unwrap(),
             Amount(MAX_MONEY)
         );
 
         let max_money_p1 = b"\x01\x40\x07\x5a\xf0\x75\x07\x00";
         assert!(Amount::from_u64_le_bytes(max_money_p1.clone()).is_err());
-        assert!(Amount::from_i64_le_bytes(max_money_p1.clone(), false).is_err());
-        assert!(Amount::from_i64_le_bytes(max_money_p1.clone(), true).is_err());
+        assert!(Amount::from_nonnegative_i64_le_bytes(max_money_p1.clone()).is_err());
+        assert!(Amount::from_i64_le_bytes(max_money_p1.clone()).is_err());
 
         let neg_max_money = b"\x00\xc0\xf8\xa5\x0f\x8a\xf8\xff";
         assert!(Amount::from_u64_le_bytes(neg_max_money.clone()).is_err());
-        assert!(Amount::from_i64_le_bytes(neg_max_money.clone(), false).is_err());
+        assert!(Amount::from_nonnegative_i64_le_bytes(neg_max_money.clone()).is_err());
         assert_eq!(
-            Amount::from_i64_le_bytes(neg_max_money.clone(), true).unwrap(),
+            Amount::from_i64_le_bytes(neg_max_money.clone()).unwrap(),
             Amount(-MAX_MONEY)
         );
 
         let neg_max_money_m1 = b"\xff\xbf\xf8\xa5\x0f\x8a\xf8\xff";
         assert!(Amount::from_u64_le_bytes(neg_max_money_m1.clone()).is_err());
-        assert!(Amount::from_i64_le_bytes(neg_max_money_m1.clone(), false).is_err());
-        assert!(Amount::from_i64_le_bytes(neg_max_money_m1.clone(), true).is_err());
+        assert!(Amount::from_nonnegative_i64_le_bytes(neg_max_money_m1.clone()).is_err());
+        assert!(Amount::from_i64_le_bytes(neg_max_money_m1.clone()).is_err());
     }
 }
diff --git a/zcash_primitives/src/transaction/mod.rs b/zcash_primitives/src/transaction/mod.rs
index e5b83e5..aac0d35 100644
--- a/zcash_primitives/src/transaction/mod.rs
+++ b/zcash_primitives/src/transaction/mod.rs
@@ -188,7 +188,7 @@ impl Transaction {
             let vb = {
                 let mut tmp = [0; 8];
                 reader.read_exact(&mut tmp)?;
-                Amount::from_i64_le_bytes(tmp, true)
+                Amount::from_i64_le_bytes(tmp)
             }
             .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "valueBalance out of range"))?;
             let ss = Vector::read(&mut reader, SpendDescription::read)?;
diff --git a/zcash_primitives/src/transaction/tests.rs b/zcash_primitives/src/transaction/tests.rs
index 7d84100..4cd5d72 100644
--- a/zcash_primitives/src/transaction/tests.rs
+++ b/zcash_primitives/src/transaction/tests.rs
@@ -1905,7 +1905,7 @@ fn zip_0143() {
             Some((
                 n as usize,
                 Script(tv.script_code),
-                Amount::from_i64(tv.amount, false).unwrap(),
+                Amount::from_nonnegative_i64(tv.amount).unwrap(),
             ))
         } else {
             None
@@ -5400,7 +5400,7 @@ fn zip_0243() {
             Some((
                 n as usize,
                 Script(tv.script_code),
-                Amount::from_i64(tv.amount, false).unwrap(),
+                Amount::from_nonnegative_i64(tv.amount).unwrap(),
             ))
         } else {
             None