diff --git a/accounts/abi/bind/util_test.go b/accounts/abi/bind/util_test.go
index 592465f2ac..5a0e5309b2 100644
--- a/accounts/abi/bind/util_test.go
+++ b/accounts/abi/bind/util_test.go
@@ -87,7 +87,7 @@ func TestWaitDeployed(t *testing.T) {
 
 		select {
 		case <-mined:
-			if err != test.wantErr {
+			if !errors.Is(err, test.wantErr) {
 				t.Errorf("test %q: error mismatch: want %q, got %q", name, test.wantErr, err)
 			}
 			if address != test.wantAddress {
diff --git a/accounts/abi/unpack_test.go b/accounts/abi/unpack_test.go
index 29891ec0a4..3fa25c25ef 100644
--- a/accounts/abi/unpack_test.go
+++ b/accounts/abi/unpack_test.go
@@ -1106,7 +1106,7 @@ func TestPackAndUnpackIncompatibleNumber(t *testing.T) {
 			{Type: ty},
 		}
 		decoded, err := decodeABI.Unpack(packed)
-		if err != testCase.err {
+		if !errors.Is(err, testCase.err) {
 			t.Fatalf("Expected error %v, actual error %v. case %d", testCase.err, err, i)
 		}
 		if err != nil {
diff --git a/accounts/keystore/keystore_test.go b/accounts/keystore/keystore_test.go
index f8922a3f3f..5d297bf882 100644
--- a/accounts/keystore/keystore_test.go
+++ b/accounts/keystore/keystore_test.go
@@ -17,6 +17,7 @@
 package keystore
 
 import (
+	"errors"
 	"math/rand"
 	"os"
 	"runtime"
@@ -127,7 +128,7 @@ func TestTimedUnlock(t *testing.T) {
 
 	// Signing without passphrase fails because account is locked
 	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
-	if err != ErrLocked {
+	if !errors.Is(err, ErrLocked) {
 		t.Fatal("Signing should've failed with ErrLocked before unlocking, got ", err)
 	}
 
@@ -145,7 +146,7 @@ func TestTimedUnlock(t *testing.T) {
 	// Signing fails again after automatic locking
 	time.Sleep(250 * time.Millisecond)
 	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
-	if err != ErrLocked {
+	if !errors.Is(err, ErrLocked) {
 		t.Fatal("Signing should've failed with ErrLocked timeout expired, got ", err)
 	}
 }
@@ -185,7 +186,7 @@ func TestOverrideUnlock(t *testing.T) {
 	// Signing fails again after automatic locking
 	time.Sleep(250 * time.Millisecond)
 	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
-	if err != ErrLocked {
+	if !errors.Is(err, ErrLocked) {
 		t.Fatal("Signing should've failed with ErrLocked timeout expired, got ", err)
 	}
 }
diff --git a/cmd/geth/accountcmd.go b/cmd/geth/accountcmd.go
index cc22684e0b..10cce92e15 100644
--- a/cmd/geth/accountcmd.go
+++ b/cmd/geth/accountcmd.go
@@ -17,15 +17,17 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"os"
 
+	"github.com/urfave/cli/v2"
+
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/accounts/keystore"
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/log"
-	"github.com/urfave/cli/v2"
 )
 
 var (
@@ -237,7 +239,7 @@ func unlockAccount(ks *keystore.KeyStore, address string, i int, passwords []str
 			log.Info("Unlocked account", "address", account.Address.Hex())
 			return ambiguousAddrRecovery(ks, err, password), password
 		}
-		if err != keystore.ErrDecrypt {
+		if !errors.Is(err, keystore.ErrDecrypt) {
 			// No need to prompt again if the error is not decryption-related.
 			break
 		}
diff --git a/cmd/rlpdump/main.go b/cmd/rlpdump/main.go
index 7e1d314d49..17b4429756 100644
--- a/cmd/rlpdump/main.go
+++ b/cmd/rlpdump/main.go
@@ -22,6 +22,7 @@ import (
 	"bytes"
 	"container/list"
 	"encoding/hex"
+	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -106,7 +107,7 @@ func rlpToText(in *inStream, out io.Writer) error {
 	stream := rlp.NewStream(in, 0)
 	for {
 		if err := dump(in, stream, 0, out); err != nil {
-			if err != io.EOF {
+			if !errors.Is(err, io.EOF) {
 				return err
 			}
 			break
diff --git a/common/bitutil/compress_test.go b/common/bitutil/compress_test.go
index c6f6fe8bcf..443c198808 100644
--- a/common/bitutil/compress_test.go
+++ b/common/bitutil/compress_test.go
@@ -18,6 +18,7 @@ package bitutil
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"math/rand"
 	"testing"
@@ -107,7 +108,7 @@ func TestDecodingCycle(t *testing.T) {
 		data := hexutil.MustDecode(tt.input)
 
 		orig, err := bitsetDecodeBytes(data, tt.size)
-		if err != tt.fail {
+		if !errors.Is(err, tt.fail) {
 			t.Errorf("test %d: failure mismatch: have %v, want %v", i, err, tt.fail)
 		}
 		if err != nil {
diff --git a/core/blockchain.go b/core/blockchain.go
index 05ebfd18b8..85232897a6 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -1391,7 +1391,7 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 	// Write downloaded chain data and corresponding receipt chain data
 	if len(ancientBlocks) > 0 {
 		if n, err := writeAncient(ancientBlocks, ancientReceipts); err != nil {
-			if err == errInsertionInterrupted {
+			if errors.Is(err, errInsertionInterrupted) {
 				return 0, nil
 			}
 			return n, err
@@ -1399,7 +1399,7 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 	}
 	if len(liveBlocks) > 0 {
 		if n, err := writeLive(liveBlocks, liveReceipts); err != nil {
-			if err == errInsertionInterrupted {
+			if errors.Is(err, errInsertionInterrupted) {
 				return 0, nil
 			}
 			return n, err
diff --git a/core/blockchain_test.go b/core/blockchain_test.go
index 4f28c6f5e6..e854eb3b87 100644
--- a/core/blockchain_test.go
+++ b/core/blockchain_test.go
@@ -26,6 +26,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/holiman/uint256"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/consensus"
@@ -40,7 +42,6 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/trie"
-	"github.com/holiman/uint256"
 )
 
 // So we can deterministically seed different blockchains
@@ -154,7 +155,7 @@ func testBlockChainImport(chain types.Blocks, blockchain *BlockChain) error {
 			err = blockchain.validator.ValidateBody(block)
 		}
 		if err != nil {
-			if err == ErrKnownBlock {
+			if errors.Is(err, ErrKnownBlock) {
 				continue
 			}
 			return err
diff --git a/core/rawdb/freezer_table_test.go b/core/rawdb/freezer_table_test.go
index 91b4943e59..c3fb54e477 100644
--- a/core/rawdb/freezer_table_test.go
+++ b/core/rawdb/freezer_table_test.go
@@ -19,6 +19,7 @@ package rawdb
 import (
 	"bytes"
 	"encoding/binary"
+	"errors"
 	"fmt"
 	"math/rand"
 	"os"
@@ -68,7 +69,7 @@ func TestFreezerBasics(t *testing.T) {
 	}
 	// Check that we cannot read too far
 	_, err = f.Retrieve(uint64(255))
-	if err != errOutOfBounds {
+	if !errors.Is(err, errOutOfBounds) {
 		t.Fatal(err)
 	}
 }
@@ -878,7 +879,7 @@ func checkRetrieveError(t *testing.T, f *freezerTable, items map[uint64]error) {
 		if err == nil {
 			t.Fatalf("unexpected value %x for item %d, want error %v", item, value, wantError)
 		}
-		if err != wantError {
+		if !errors.Is(err, wantError) {
 			t.Fatalf("wrong error for item %d: %v", item, err)
 		}
 	}
diff --git a/core/rawdb/freezer_test.go b/core/rawdb/freezer_test.go
index 72d1417200..abfec94cba 100644
--- a/core/rawdb/freezer_test.go
+++ b/core/rawdb/freezer_test.go
@@ -106,7 +106,7 @@ func TestFreezerModifyRollback(t *testing.T) {
 		require.NoError(t, op.AppendRaw("test", 2, make([]byte, 2048)))
 		return theError
 	})
-	if err != theError {
+	if !errors.Is(err, theError) {
 		t.Errorf("ModifyAncients returned wrong error %q", err)
 	}
 	checkAncientCount(t, f, "test", 0)
@@ -374,7 +374,7 @@ func checkAncientCount(t *testing.T, f *Freezer, kind string, n uint64) {
 	}
 	if _, err := f.Ancient(kind, index); err == nil {
 		t.Errorf("Ancient(%q, %d) didn't return expected error", kind, index)
-	} else if err != errOutOfBounds {
+	} else if !errors.Is(err, errOutOfBounds) {
 		t.Errorf("Ancient(%q, %d) returned unexpected error %q", kind, index, err)
 	}
 }
diff --git a/core/txpool/legacypool/journal.go b/core/txpool/legacypool/journal.go
index 899ed00bcc..a472615dcd 100644
--- a/core/txpool/legacypool/journal.go
+++ b/core/txpool/legacypool/journal.go
@@ -96,7 +96,7 @@ func (journal *journal) load(add func([]*types.Transaction) []error) error {
 		// Parse the next transaction and terminate on error
 		tx := new(types.Transaction)
 		if err = stream.Decode(tx); err != nil {
-			if err != io.EOF {
+			if !errors.Is(err, io.EOF) {
 				failure = err
 			}
 			if batch.Len() > 0 {
diff --git a/core/types/receipt_test.go b/core/types/receipt_test.go
index fc51eb11a5..8ecfa0dbf1 100644
--- a/core/types/receipt_test.go
+++ b/core/types/receipt_test.go
@@ -19,6 +19,7 @@ package types
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"math"
 	"math/big"
 	"reflect"
@@ -300,7 +301,7 @@ func TestDecodeEmptyTypedReceipt(t *testing.T) {
 	input := []byte{0x80}
 	var r Receipt
 	err := rlp.DecodeBytes(input, &r)
-	if err != errShortTypedReceipt {
+	if !errors.Is(err, errShortTypedReceipt) {
 		t.Fatal("wrong error:", err)
 	}
 }
diff --git a/core/types/transaction_test.go b/core/types/transaction_test.go
index eed13ee205..169261d819 100644
--- a/core/types/transaction_test.go
+++ b/core/types/transaction_test.go
@@ -76,7 +76,7 @@ func TestDecodeEmptyTypedTx(t *testing.T) {
 	input := []byte{0x80}
 	var tx Transaction
 	err := rlp.DecodeBytes(input, &tx)
-	if err != errShortTypedTx {
+	if !errors.Is(err, errShortTypedTx) {
 		t.Fatal("wrong error:", err)
 	}
 }
@@ -571,7 +571,7 @@ func TestYParityJSONUnmarshalling(t *testing.T) {
 				// Unmarshal the tx
 				var tx Transaction
 				err = tx.UnmarshalJSON(jsonBytes)
-				if err != test.wantErr {
+				if !errors.Is(err, test.wantErr) {
 					t.Fatalf("wrong error: got %v, want %v", err, test.wantErr)
 				}
 			})
diff --git a/core/vm/evm.go b/core/vm/evm.go
index 1944189b5d..c997d6a195 100644
--- a/core/vm/evm.go
+++ b/core/vm/evm.go
@@ -251,7 +251,7 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 	// when we're in homestead this also counts for code storage gas errors.
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != ErrExecutionReverted {
+		if !errors.Is(err, ErrExecutionReverted) {
 			if evm.Config.Tracer != nil && evm.Config.Tracer.OnGasChange != nil {
 				evm.Config.Tracer.OnGasChange(gas, 0, tracing.GasChangeCallFailedExecution)
 			}
@@ -310,7 +310,7 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
 	}
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != ErrExecutionReverted {
+		if !errors.Is(err, ErrExecutionReverted) {
 			if evm.Config.Tracer != nil && evm.Config.Tracer.OnGasChange != nil {
 				evm.Config.Tracer.OnGasChange(gas, 0, tracing.GasChangeCallFailedExecution)
 			}
@@ -360,7 +360,7 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
 	}
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != ErrExecutionReverted {
+		if !errors.Is(err, ErrExecutionReverted) {
 			if evm.Config.Tracer != nil && evm.Config.Tracer.OnGasChange != nil {
 				evm.Config.Tracer.OnGasChange(gas, 0, tracing.GasChangeCallFailedExecution)
 			}
@@ -421,7 +421,7 @@ func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte
 	}
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != ErrExecutionReverted {
+		if !errors.Is(err, ErrExecutionReverted) {
 			if evm.Config.Tracer != nil && evm.Config.Tracer.OnGasChange != nil {
 				evm.Config.Tracer.OnGasChange(gas, 0, tracing.GasChangeCallFailedExecution)
 			}
@@ -562,7 +562,7 @@ func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64,
 	// when we're in homestead this also counts for code storage gas errors.
 	if err != nil && (evm.chainRules.IsHomestead || err != ErrCodeStoreOutOfGas) {
 		evm.StateDB.RevertToSnapshot(snapshot)
-		if err != ErrExecutionReverted {
+		if !errors.Is(err, ErrExecutionReverted) {
 			contract.UseGas(contract.Gas, evm.Config.Tracer, tracing.GasChangeCallFailedExecution)
 		}
 	}
diff --git a/crypto/ecies/ecies_test.go b/crypto/ecies/ecies_test.go
index e3da71010e..0b3a2e070c 100644
--- a/crypto/ecies/ecies_test.go
+++ b/crypto/ecies/ecies_test.go
@@ -152,12 +152,12 @@ func TestTooBigSharedKey(t *testing.T) {
 	}
 
 	_, err = prv1.GenerateShared(&prv2.PublicKey, 32, 32)
-	if err != ErrSharedKeyTooBig {
+	if !errors.Is(err, ErrSharedKeyTooBig) {
 		t.Fatal("ecdh: shared key should be too large for curve")
 	}
 
 	_, err = prv2.GenerateShared(&prv1.PublicKey, 32, 32)
-	if err != ErrSharedKeyTooBig {
+	if !errors.Is(err, ErrSharedKeyTooBig) {
 		t.Fatal("ecdh: shared key should be too large for curve")
 	}
 }
@@ -355,7 +355,7 @@ func TestBasicKeyValidation(t *testing.T) {
 	for _, b := range badBytes {
 		ct[0] = b
 		_, err := prv.Decrypt(ct, nil, nil)
-		if err != ErrInvalidPublicKey {
+		if !errors.Is(err, ErrInvalidPublicKey) {
 			t.Fatal("ecies: validated an invalid key")
 		}
 	}
diff --git a/crypto/secp256k1/secp256_test.go b/crypto/secp256k1/secp256_test.go
index 4827cc5b25..9a501999de 100644
--- a/crypto/secp256k1/secp256_test.go
+++ b/crypto/secp256k1/secp256_test.go
@@ -12,6 +12,7 @@ import (
 	"crypto/ecdsa"
 	"crypto/rand"
 	"encoding/hex"
+	"errors"
 	"io"
 	"testing"
 )
@@ -91,7 +92,7 @@ func TestInvalidRecoveryID(t *testing.T) {
 	sig, _ := Sign(msg, seckey)
 	sig[64] = 99
 	_, err := RecoverPubkey(msg, sig)
-	if err != ErrInvalidRecoveryID {
+	if !errors.Is(err, ErrInvalidRecoveryID) {
 		t.Fatalf("got %q, want %q", err, ErrInvalidRecoveryID)
 	}
 }
diff --git a/eth/filters/filter_test.go b/eth/filters/filter_test.go
index 2b3efb51b1..a94529a1c1 100644
--- a/eth/filters/filter_test.go
+++ b/eth/filters/filter_test.go
@@ -19,6 +19,7 @@ package filters
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"math/big"
 	"strings"
 	"testing"
@@ -382,7 +383,7 @@ func TestFilters(t *testing.T) {
 		if err == nil {
 			t.Fatal("expected error")
 		}
-		if err != context.DeadlineExceeded {
+		if !errors.Is(err, context.DeadlineExceeded) {
 			t.Fatalf("expected context.DeadlineExceeded, got %v", err)
 		}
 	})
diff --git a/event/subscription_test.go b/event/subscription_test.go
index 743d0bf67d..2cd5d4e7c9 100644
--- a/event/subscription_test.go
+++ b/event/subscription_test.go
@@ -56,7 +56,7 @@ loop:
 				t.Fatalf("wrong int %d, want %d", got, want)
 			}
 		case err := <-sub.Err():
-			if err != errInts {
+			if !errors.Is(err, errInts) {
 				t.Fatalf("wrong error: got %q, want %q", err, errInts)
 			}
 			if want != 2 {
diff --git a/node/node_test.go b/node/node_test.go
index 82e814cada..a30fad8fb2 100644
--- a/node/node_test.go
+++ b/node/node_test.go
@@ -101,7 +101,7 @@ func TestNodeUsedDataDir(t *testing.T) {
 
 	// Create a second node based on the same data directory and ensure failure
 	_, err = New(&Config{DataDir: dir})
-	if err != ErrDatadirUsed {
+	if !errors.Is(err, ErrDatadirUsed) {
 		t.Fatalf("duplicate datadir failure mismatch: have %v, want %v", err, ErrDatadirUsed)
 	}
 }
diff --git a/p2p/discover/v4_udp_test.go b/p2p/discover/v4_udp_test.go
index 1af31f4f1b..0d34db9470 100644
--- a/p2p/discover/v4_udp_test.go
+++ b/p2p/discover/v4_udp_test.go
@@ -211,7 +211,7 @@ func TestUDPv4_responseTimeouts(t *testing.T) {
 	for i := 0; i < nReqs; i++ {
 		select {
 		case err := <-timeoutErr:
-			if err != errTimeout {
+			if !errors.Is(err, errTimeout) {
 				t.Fatalf("got non-timeout error on timeoutErr %d: %v", i, err)
 			}
 			nTimeoutsRecv++
@@ -241,7 +241,7 @@ func TestUDPv4_findnodeTimeout(t *testing.T) {
 	toid := enode.ID{1, 2, 3, 4}
 	target := v4wire.Pubkey{4, 5, 6, 7}
 	result, err := test.udp.findnode(toid, toaddr, target)
-	if err != errTimeout {
+	if !errors.Is(err, errTimeout) {
 		t.Error("expected timeout error, got", err)
 	}
 	if len(result) > 0 {
diff --git a/p2p/dnsdisc/client_test.go b/p2p/dnsdisc/client_test.go
index 01912e1eab..f8b697d1ac 100644
--- a/p2p/dnsdisc/client_test.go
+++ b/p2p/dnsdisc/client_test.go
@@ -26,6 +26,7 @@ import (
 	"time"
 
 	"github.com/davecgh/go-spew/spew"
+
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/common/mclock"
 	"github.com/ethereum/go-ethereum/crypto"
@@ -95,7 +96,7 @@ func TestClientSyncTreeBadNode(t *testing.T) {
 	c := NewClient(Config{Resolver: r, Logger: testlog.Logger(t, log.LvlTrace)})
 	_, err := c.SyncTree("enrtree://AKPYQIUQIL7PSIACI32J7FGZW56E5FKHEFCCOFHILBIMW3M6LWXS2@n")
 	wantErr := nameError{name: "INDMVBZEEQ4ESVYAKGIYU74EAA.n", err: entryError{typ: "enr", err: errInvalidENR}}
-	if err != wantErr {
+	if !errors.Is(err, wantErr) {
 		t.Fatalf("expected sync error %q, got %q", wantErr, err)
 	}
 }
diff --git a/p2p/dnsdisc/tree_test.go b/p2p/dnsdisc/tree_test.go
index 9ed17aa4b3..eb06b995db 100644
--- a/p2p/dnsdisc/tree_test.go
+++ b/p2p/dnsdisc/tree_test.go
@@ -17,10 +17,12 @@
 package dnsdisc
 
 import (
+	"errors"
 	"reflect"
 	"testing"
 
 	"github.com/davecgh/go-spew/spew"
+
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 )
@@ -54,7 +56,7 @@ func TestParseRoot(t *testing.T) {
 		if !reflect.DeepEqual(e, test.e) {
 			t.Errorf("test %d: wrong entry %s, want %s", i, spew.Sdump(e), spew.Sdump(test.e))
 		}
-		if err != test.err {
+		if !errors.Is(err, test.err) {
 			t.Errorf("test %d: wrong error %q, want %q", i, err, test.err)
 		}
 	}
@@ -131,7 +133,7 @@ func TestParseEntry(t *testing.T) {
 		if !reflect.DeepEqual(e, test.e) {
 			t.Errorf("test %d: wrong entry %s, want %s", i, spew.Sdump(e), spew.Sdump(test.e))
 		}
-		if err != test.err {
+		if !errors.Is(err, test.err) {
 			t.Errorf("test %d: wrong error %q, want %q", i, err, test.err)
 		}
 	}
diff --git a/p2p/enr/enr_test.go b/p2p/enr/enr_test.go
index 4fccb0cce9..b7c20704af 100644
--- a/p2p/enr/enr_test.go
+++ b/p2p/enr/enr_test.go
@@ -19,14 +19,16 @@ package enr
 import (
 	"bytes"
 	"encoding/binary"
+	"errors"
 	"fmt"
 	"math/rand"
 	"testing"
 	"time"
 
-	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"github.com/ethereum/go-ethereum/rlp"
 )
 
 var rnd = rand.New(rand.NewSource(time.Now().UnixNano()))
@@ -274,7 +276,7 @@ func TestDecodeIncomplete(t *testing.T) {
 	for _, test := range tests {
 		var r Record
 		err := rlp.DecodeBytes(test.input, &r)
-		if err != test.err {
+		if !errors.Is(err, test.err) {
 			t.Errorf("wrong error for %X: %v", test.input, err)
 		}
 	}
diff --git a/p2p/message_test.go b/p2p/message_test.go
index e575c5d96e..37fee20312 100644
--- a/p2p/message_test.go
+++ b/p2p/message_test.go
@@ -18,6 +18,7 @@ package p2p
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"runtime"
@@ -55,7 +56,7 @@ loop:
 		go func() {
 			if err := SendItems(rw1, 1); err == nil {
 				t.Error("EncodeMsg returned nil error")
-			} else if err != ErrPipeClosed {
+			} else if !errors.Is(err, ErrPipeClosed) {
 				t.Errorf("EncodeMsg returned wrong error: got %v, want %v", err, ErrPipeClosed)
 			}
 			close(done)
diff --git a/p2p/netutil/net_test.go b/p2p/netutil/net_test.go
index 569c7ac454..ccc57c28a9 100644
--- a/p2p/netutil/net_test.go
+++ b/p2p/netutil/net_test.go
@@ -17,6 +17,7 @@
 package netutil
 
 import (
+	"errors"
 	"fmt"
 	"math/rand"
 	"net"
@@ -178,7 +179,7 @@ func TestCheckRelayIP(t *testing.T) {
 
 	for _, test := range tests {
 		err := CheckRelayIP(parseIP(test.sender), parseIP(test.addr))
-		if err != test.want {
+		if !errors.Is(err, test.want) {
 			t.Errorf("%s from %s: got %q, want %q", test.addr, test.sender, err, test.want)
 		}
 	}
diff --git a/p2p/peer_test.go b/p2p/peer_test.go
index 4308bbd2eb..91862f14a1 100644
--- a/p2p/peer_test.go
+++ b/p2p/peer_test.go
@@ -138,7 +138,7 @@ func TestPeerProtoReadMsg(t *testing.T) {
 
 	select {
 	case err := <-errc:
-		if err != errProtocolReturned {
+		if !errors.Is(err, errProtocolReturned) {
 			t.Errorf("peer returned error: %v", err)
 		}
 	case <-time.After(2 * time.Second):
diff --git a/rlp/raw_test.go b/rlp/raw_test.go
index 7b3255eca3..9e804060a8 100644
--- a/rlp/raw_test.go
+++ b/rlp/raw_test.go
@@ -129,7 +129,7 @@ func TestSplitUint64(t *testing.T) {
 		if !bytes.Equal(rest, unhex(test.rest)) {
 			t.Errorf("test %d: rest mismatch: got %x, want %s (input %q)", i, rest, test.rest, test.input)
 		}
-		if err != test.err {
+		if !errors.Is(err, test.err) {
 			t.Errorf("test %d: error mismatch: got %q, want %q", i, err, test.err)
 		}
 	}
@@ -213,7 +213,7 @@ func TestSplit(t *testing.T) {
 		if !bytes.Equal(rest, unhex(test.rest)) {
 			t.Errorf("test %d: rest mismatch: got %x, want %s", i, rest, test.rest)
 		}
-		if err != test.err {
+		if !errors.Is(err, test.err) {
 			t.Errorf("test %d: error mismatch: got %q, want %q", i, err, test.err)
 		}
 	}
@@ -251,7 +251,7 @@ func TestReadSize(t *testing.T) {
 
 	for _, test := range tests {
 		size, err := readSize(unhex(test.input), test.slen)
-		if err != test.err {
+		if !errors.Is(err, test.err) {
 			t.Errorf("readSize(%s, %d): error mismatch: got %q, want %q", test.input, test.slen, err, test.err)
 			continue
 		}
diff --git a/rpc/server.go b/rpc/server.go
index 42b59f8f6f..5460afc2e0 100644
--- a/rpc/server.go
+++ b/rpc/server.go
@@ -174,7 +174,7 @@ func messageForReadError(err error) string {
 		} else {
 			return "read error"
 		}
-	} else if err != io.EOF {
+	} else if !errors.Is(err, io.EOF) {
 		return "parse error"
 	}
 	return ""
diff --git a/signer/core/api.go b/signer/core/api.go
index 23ddcd0a20..ea266e9ed7 100644
--- a/signer/core/api.go
+++ b/signer/core/api.go
@@ -332,7 +332,7 @@ func (api *SignerAPI) startUSBListener() {
 	for _, wallet := range am.Wallets() {
 		if err := wallet.Open(""); err != nil {
 			log.Warn("Failed to open wallet", "url", wallet.URL(), "err", err)
-			if err == usbwallet.ErrTrezorPINNeeded {
+			if errors.Is(err, usbwallet.ErrTrezorPINNeeded) {
 				go api.openTrezor(wallet.URL())
 			}
 		}
@@ -348,7 +348,7 @@ func (api *SignerAPI) derivationLoop(events chan accounts.WalletEvent) {
 		case accounts.WalletArrived:
 			if err := event.Wallet.Open(""); err != nil {
 				log.Warn("New wallet appeared, failed to open", "url", event.Wallet.URL(), "err", err)
-				if err == usbwallet.ErrTrezorPINNeeded {
+				if errors.Is(err, usbwallet.ErrTrezorPINNeeded) {
 					go api.openTrezor(event.Wallet.URL())
 				}
 			}
diff --git a/signer/core/api_test.go b/signer/core/api_test.go
index 69229dadaf..17a7eb1876 100644
--- a/signer/core/api_test.go
+++ b/signer/core/api_test.go
@@ -19,6 +19,7 @@ package core_test
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"math/big"
 	"os"
@@ -155,7 +156,7 @@ func failCreateAccountWithPassword(ui *headlessUi, api *core.SignerAPI, password
 func failCreateAccount(ui *headlessUi, api *core.SignerAPI, t *testing.T) {
 	ui.approveCh <- "N"
 	addr, err := api.New(context.Background())
-	if err != core.ErrRequestDenied {
+	if !errors.Is(err, core.ErrRequestDenied) {
 		t.Fatal(err)
 	}
 	if addr != (common.Address{}) {
@@ -212,7 +213,7 @@ func TestNewAcc(t *testing.T) {
 	if len(list) != 0 {
 		t.Fatalf("List should be empty")
 	}
-	if err != core.ErrRequestDenied {
+	if !errors.Is(err, core.ErrRequestDenied) {
 		t.Fatal("Expected deny")
 	}
 }
@@ -264,7 +265,7 @@ func TestSignTx(t *testing.T) {
 	if res != nil {
 		t.Errorf("Expected nil-response, got %v", res)
 	}
-	if err != keystore.ErrDecrypt {
+	if !errors.Is(err, keystore.ErrDecrypt) {
 		t.Errorf("Expected ErrLocked! %v", err)
 	}
 	control.approveCh <- "No way"
@@ -272,7 +273,7 @@ func TestSignTx(t *testing.T) {
 	if res != nil {
 		t.Errorf("Expected nil-response, got %v", res)
 	}
-	if err != core.ErrRequestDenied {
+	if !errors.Is(err, core.ErrRequestDenied) {
 		t.Errorf("Expected ErrRequestDenied! %v", err)
 	}
 	// Sign with correct password
diff --git a/signer/core/signed_data_test.go b/signer/core/signed_data_test.go
index d0637010ba..10d5ff3d06 100644
--- a/signer/core/signed_data_test.go
+++ b/signer/core/signed_data_test.go
@@ -20,6 +20,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"math/big"
 	"os"
@@ -201,7 +202,7 @@ func TestSignData(t *testing.T) {
 	if signature != nil {
 		t.Errorf("Expected nil-data, got %x", signature)
 	}
-	if err != keystore.ErrDecrypt {
+	if !errors.Is(err, keystore.ErrDecrypt) {
 		t.Errorf("Expected ErrLocked! '%v'", err)
 	}
 	control.approveCh <- "No way"
@@ -209,7 +210,7 @@ func TestSignData(t *testing.T) {
 	if signature != nil {
 		t.Errorf("Expected nil-data, got %x", signature)
 	}
-	if err != core.ErrRequestDenied {
+	if !errors.Is(err, core.ErrRequestDenied) {
 		t.Errorf("Expected ErrRequestDenied! '%v'", err)
 	}
 	// text/plain