diff --git a/beacon/types/exec_payload.go b/beacon/types/exec_payload.go
index 4448f854ad..b159687dfc 100644
--- a/beacon/types/exec_payload.go
+++ b/beacon/types/exec_payload.go
@@ -65,7 +65,7 @@ func convertPayload[T payloadType](payload T, parentRoot *zrntcommon.Root) (*typ
 
 	block := types.NewBlockWithHeader(&header).WithBody(types.Body{Transactions: transactions, Withdrawals: withdrawals})
 	if hash := block.Hash(); hash != expectedHash {
-		return nil, fmt.Errorf("Sanity check failed, payload hash does not match (expected %x, got %x)", expectedHash, hash)
+		return nil, fmt.Errorf("sanity check failed, payload hash does not match (expected %x, got %x)", expectedHash, hash)
 	}
 	return block, nil
 }
diff --git a/cmd/clef/main.go b/cmd/clef/main.go
index f9b00e4a12..88d4c99e78 100644
--- a/cmd/clef/main.go
+++ b/cmd/clef/main.go
@@ -552,7 +552,7 @@ func listWallets(c *cli.Context) error {
 // accountImport imports a raw hexadecimal private key via CLI.
 func accountImport(c *cli.Context) error {
 	if c.Args().Len() != 1 {
-		return errors.New("<keyfile> must be given as first argument.")
+		return errors.New("<keyfile> must be given as first argument")
 	}
 	internalApi, ui, err := initInternalApi(c)
 	if err != nil {
diff --git a/core/chain_indexer_test.go b/core/chain_indexer_test.go
index f099609015..bf3bde756c 100644
--- a/core/chain_indexer_test.go
+++ b/core/chain_indexer_test.go
@@ -228,7 +228,7 @@ func (b *testChainIndexBackend) Process(ctx context.Context, header *types.Heade
 		b.t.Error("Unexpected call to Process")
 		// Can't use Fatal since this is not the test's goroutine.
 		// Returning error stops the chainIndexer's updateLoop
-		return errors.New("Unexpected call to Process")
+		return errors.New("unexpected call to Process")
 	case b.processCh <- header.Number.Uint64():
 	}
 	return nil
diff --git a/core/types/transaction_test.go b/core/types/transaction_test.go
index 361b977611..5dbf367073 100644
--- a/core/types/transaction_test.go
+++ b/core/types/transaction_test.go
@@ -379,7 +379,7 @@ func assertEqual(orig *Transaction, cpy *Transaction) error {
 	}
 	if orig.AccessList() != nil {
 		if !reflect.DeepEqual(orig.AccessList(), cpy.AccessList()) {
-			return errors.New("access list wrong!")
+			return errors.New("access list wrong")
 		}
 	}
 	return nil
diff --git a/eth/backend.go b/eth/backend.go
index e616b5f2f1..97e68b8cf0 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -208,7 +208,7 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
 		}
 		t, err := tracers.LiveDirectory.New(config.VMTrace, traceConfig)
 		if err != nil {
-			return nil, fmt.Errorf("Failed to create tracer %s: %v", config.VMTrace, err)
+			return nil, fmt.Errorf("failed to create tracer %s: %v", config.VMTrace, err)
 		}
 		vmConfig.Tracer = t
 	}
diff --git a/eth/catalyst/api_test.go b/eth/catalyst/api_test.go
index 0586959f06..64e6684be1 100644
--- a/eth/catalyst/api_test.go
+++ b/eth/catalyst/api_test.go
@@ -979,11 +979,11 @@ func TestSimultaneousNewBlock(t *testing.T) {
 					defer wg.Done()
 					if newResp, err := api.NewPayloadV1(*execData); err != nil {
 						errMu.Lock()
-						testErr = fmt.Errorf("Failed to insert block: %w", err)
+						testErr = fmt.Errorf("failed to insert block: %w", err)
 						errMu.Unlock()
 					} else if newResp.Status != "VALID" {
 						errMu.Lock()
-						testErr = fmt.Errorf("Failed to insert block: %v", newResp.Status)
+						testErr = fmt.Errorf("failed to insert block: %v", newResp.Status)
 						errMu.Unlock()
 					}
 				}()
@@ -1018,7 +1018,7 @@ func TestSimultaneousNewBlock(t *testing.T) {
 					defer wg.Done()
 					if _, err := api.ForkchoiceUpdatedV1(fcState, nil); err != nil {
 						errMu.Lock()
-						testErr = fmt.Errorf("Failed to insert block: %w", err)
+						testErr = fmt.Errorf("failed to insert block: %w", err)
 						errMu.Unlock()
 					}
 				}()
diff --git a/log/logger_test.go b/log/logger_test.go
index 2ea0858547..6f415eb471 100644
--- a/log/logger_test.go
+++ b/log/logger_test.go
@@ -97,7 +97,7 @@ func benchmarkLogger(b *testing.B, l Logger) {
 		tt     = time.Now()
 		bigint = big.NewInt(100)
 		nilbig *big.Int
-		err    = errors.New("Oh nooes it's crap")
+		err    = errors.New("oh nooes it's crap")
 	)
 	b.ReportAllocs()
 	b.ResetTimer()
@@ -126,7 +126,7 @@ func TestLoggerOutput(t *testing.T) {
 		tt        = time.Time{}
 		bigint    = big.NewInt(100)
 		nilbig    *big.Int
-		err       = errors.New("Oh nooes it's crap")
+		err       = errors.New("oh nooes it's crap")
 		smallUint = uint256.NewInt(500_000)
 		bigUint   = &uint256.Int{0xff, 0xff, 0xff, 0xff}
 	)
@@ -150,7 +150,7 @@ func TestLoggerOutput(t *testing.T) {
 
 	have := out.String()
 	t.Logf("output %v", out.String())
-	want := `INFO [11-07|19:14:33.821] This is a message                        foo=123 bytes="[0 0 0 0 0 0 0 0 0 0]" bonk="a string with text" time=0001-01-01T00:00:00+0000 bigint=100 nilbig=<nil> err="Oh nooes it's crap" struct="{A:Foo B:12}" struct="{A:Foo\nLinebreak B:122}" ptrstruct="&{A:Foo B:12}" smalluint=500,000 bigUint=1,600,660,942,523,603,594,864,898,306,482,794,244,293,965,082,972,225,630,372,095
+	want := `INFO [11-07|19:14:33.821] This is a message                        foo=123 bytes="[0 0 0 0 0 0 0 0 0 0]" bonk="a string with text" time=0001-01-01T00:00:00+0000 bigint=100 nilbig=<nil> err="oh nooes it's crap" struct="{A:Foo B:12}" struct="{A:Foo\nLinebreak B:122}" ptrstruct="&{A:Foo B:12}" smalluint=500,000 bigUint=1,600,660,942,523,603,594,864,898,306,482,794,244,293,965,082,972,225,630,372,095
 `
 	if !bytes.Equal([]byte(have)[25:], []byte(want)[25:]) {
 		t.Errorf("Error\nhave: %q\nwant: %q", have, want)