diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py
index 2bac77de81..28bcc516c6 100755
--- a/test/functional/rpc_psbt.py
+++ b/test/functional/rpc_psbt.py
@@ -193,7 +193,52 @@ class PSBTTest(BitcoinTestFramework):
         res = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"feeRate": 0.1, "add_inputs": True})
         assert_approx(res["fee"], 0.055, 0.005)
 
-        self.log.info("Test walletcreatefundedpsbt feeRate of 10 BTC/KB produces total fee well above -maxtxfee and raises RPC error")
+        self.log.info("Test walletcreatefundedpsbt explicit fee rate with conf_target and estimate_mode")
+        for unit, fee_rate in {"btc/kb": 0.1, "sat/b": 10000}.items():
+            fee = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"conf_target": fee_rate, "estimate_mode": unit, "add_inputs": True})["fee"]
+            self.log.info("- conf_target {}, estimate_mode {} produces fee {} at or slightly below -maxtxfee (~0.05290000)".format(fee_rate, unit, fee))
+            assert_approx(fee, vexp=0.055, vspan=0.005)
+
+        for field, fee_rate in {"conf_target": 0.1, "estimate_mode": "sat/b"}.items():
+            self.log.info("- raises RPC error if both feeRate and {} are passed".format(field))
+            assert_raises_rpc_error(-8, "Cannot specify both {} and feeRate".format(field),
+                lambda: self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"feeRate": 0.1, field: fee_rate, "add_inputs": True}))
+
+        self.log.info("- raises RPC error with invalid estimate_mode settings")
+        for k, v in {"number": 42, "object": {"foo": "bar"}}.items():
+            assert_raises_rpc_error(-3, "Expected type string for estimate_mode, got {}".format(k),
+                lambda: self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"estimate_mode": v, "conf_target": 0.1, "add_inputs": True}))
+        for mode in ["foo", Decimal("3.141592")]:
+            assert_raises_rpc_error(-8, "Invalid estimate_mode parameter",
+                lambda: self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"estimate_mode": mode, "conf_target": 0.1, "add_inputs": True}))
+
+        self.log.info("- raises RPC error if estimate_mode is passed without a conf_target")
+        for unit in ["SAT/B", "BTC/KB"]:
+            assert_raises_rpc_error(-8, "Selected estimate_mode {} requires a fee rate to be specified in conf_target".format(unit),
+                lambda: self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"estimate_mode": unit}))
+
+        self.log.info("- raises RPC error with invalid conf_target settings")
+        for mode in ["unset", "economical", "conservative", "btc/kb", "sat/b"]:
+            self.log.debug("{}".format(mode))
+            for k, v in {"string": "", "object": {"foo": "bar"}}.items():
+                assert_raises_rpc_error(-3, "Expected type number for conf_target, got {}".format(k),
+                    lambda: self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"estimate_mode": mode, "conf_target": v, "add_inputs": True}))
+            if mode in ["btc/kb", "sat/b"]:
+                assert_raises_rpc_error(-3, "Amount out of range",
+                    lambda: self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"estimate_mode": mode, "conf_target": -1, "add_inputs": True}))
+                assert_raises_rpc_error(-4, "Fee rate (0.00000000 BTC/kB) is lower than the minimum fee rate setting (0.00001000 BTC/kB)",
+                    lambda: self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"estimate_mode": mode, "conf_target": 0, "add_inputs": True}))
+            else:
+                for n in [-1, 0, 1009]:
+                    assert_raises_rpc_error(-8, "Invalid conf_target, must be between 1 and 1008",
+                        lambda: self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"estimate_mode": mode, "conf_target": n, "add_inputs": True}))
+
+        for unit, fee_rate in {"SAT/B": 0.99999999, "BTC/KB": 0.00000999}.items():
+            self.log.info("- raises RPC error 'fee rate too low' if conf_target {} and estimate_mode {} are passed".format(fee_rate, unit))
+            assert_raises_rpc_error(-4, "Fee rate (0.00000999 BTC/kB) is lower than the minimum fee rate setting (0.00001000 BTC/kB)",
+                lambda: self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"estimate_mode": unit, "conf_target": fee_rate, "add_inputs": True}))
+
+        self.log.info("Test walletcreatefundedpsbt feeRate of 10 BTC/kB produces total fee well above -maxtxfee and raises RPC error")
         # previously this was silently capped at -maxtxfee
         for bool_add, outputs_array in {True: outputs, False: [{self.nodes[1].getnewaddress(): 1}]}.items():
             assert_raises_rpc_error(-4, "Fee exceeds maximum configured by user (e.g. -maxtxfee, maxfeerate)",