diff --git a/test/functional/abc_rpc_avalancheproof.py b/test/functional/abc_rpc_avalancheproof.py
--- a/test/functional/abc_rpc_avalancheproof.py
+++ b/test/functional/abc_rpc_avalancheproof.py
@@ -281,11 +281,10 @@
             proof_sequence, proof_expiration, wif_privkey,
             create_coinbase_stakes(node, [blockhashes[0]], addrkey0.key, amount="0"))
 
-        dust_amount = Decimal(f"{PROOF_DUST_THRESHOLD * 0.9999:.4f}")
         dust2 = node.buildavalancheproof(
             proof_sequence, proof_expiration, wif_privkey,
             create_coinbase_stakes(node, [blockhashes[0]], addrkey0.key,
-                                   amount=str(dust_amount)))
+                                   amount=f"{PROOF_DUST_THRESHOLD * 0.9999:.2f}"))
 
         missing_stake = node.buildavalancheproof(
             proof_sequence, proof_expiration, wif_privkey, [{
diff --git a/test/functional/rpc_fundrawtransaction.py b/test/functional/rpc_fundrawtransaction.py
--- a/test/functional/rpc_fundrawtransaction.py
+++ b/test/functional/rpc_fundrawtransaction.py
@@ -835,7 +835,7 @@
         # Output 0 takes at least as much share of the fee, and no more than 2
         # satoshis more, than outputs 2 and 3.
         assert_greater_than_or_equal(share[0], share[2])
-        assert_greater_than_or_equal(share[2] + Decimal(2e-8), share[0])
+        assert_greater_than_or_equal(share[2] + Decimal("2e-8"), share[0])
 
         # The fee is the same in both transactions.
         assert_equal(result[0]['fee'], result[1]['fee'])
diff --git a/test/functional/wallet_send.py b/test/functional/wallet_send.py
--- a/test/functional/wallet_send.py
+++ b/test/functional/wallet_send.py
@@ -294,7 +294,7 @@
             add_to_wallet=False)
         fee = self.nodes[1].decodepsbt(res["psbt"])["fee"]
         assert_fee_amount(fee,
-                          Decimal(len(res["hex"]) / 2),
+                          len(res["hex"]) // 2,
                           Decimal("20.00"))
         self.test_send(from_wallet=w0, to_wallet=w1, amount=1_000_000, fee_rate=-1,
                        expect_error=(-3, "Amount out of range"))