diff --git a/internal/era/e2store/e2store_test.go b/internal/era/e2store/e2store_test.go
index b0803493c7..353942f0bd 100644
--- a/internal/era/e2store/e2store_test.go
+++ b/internal/era/e2store/e2store_test.go
@@ -26,6 +26,8 @@ import (
 )
 
 func TestEncode(t *testing.T) {
+	t.Parallel()
+
 	for _, test := range []struct {
 		entries []Entry
 		want    string
@@ -53,6 +55,7 @@ func TestEncode(t *testing.T) {
 		tt := test
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
+
 			var (
 				b = bytes.NewBuffer(nil)
 				w = NewWriter(b)
@@ -83,6 +86,8 @@ func TestEncode(t *testing.T) {
 }
 
 func TestDecode(t *testing.T) {
+	t.Parallel()
+
 	for i, tt := range []struct {
 		have string
 		err  error
diff --git a/internal/era/era_test.go b/internal/era/era_test.go
index 883e30f7b6..d0f56b6f88 100644
--- a/internal/era/era_test.go
+++ b/internal/era/era_test.go
@@ -34,6 +34,8 @@ type testchain struct {
 }
 
 func TestEra1Builder(t *testing.T) {
+	t.Parallel()
+
 	// Get temp directory.
 	f, err := os.CreateTemp("", "era1-test")
 	if err != nil {
@@ -125,6 +127,8 @@ func TestEra1Builder(t *testing.T) {
 }
 
 func TestEraFilename(t *testing.T) {
+	t.Parallel()
+
 	for i, tt := range []struct {
 		network  string
 		epoch    int
diff --git a/internal/ethapi/api_test.go b/internal/ethapi/api_test.go
index f2dd93e4ac..384ca9f1cc 100644
--- a/internal/ethapi/api_test.go
+++ b/internal/ethapi/api_test.go
@@ -61,7 +61,6 @@ import (
 )
 
 func testTransactionMarshal(t *testing.T, tests []txData, config *params.ChainConfig) {
-	t.Parallel()
 	var (
 		signer = types.LatestSigner(config)
 		key, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
@@ -98,6 +97,8 @@ func testTransactionMarshal(t *testing.T, tests []txData, config *params.ChainCo
 }
 
 func TestTransaction_RoundTripRpcJSON(t *testing.T) {
+	t.Parallel()
+
 	var (
 		config = params.AllEthashProtocolChanges
 		tests  = allTransactionTypes(common.Address{0xde, 0xad}, config)
@@ -106,6 +107,8 @@ func TestTransaction_RoundTripRpcJSON(t *testing.T) {
 }
 
 func TestTransactionBlobTx(t *testing.T) {
+	t.Parallel()
+
 	config := *params.TestChainConfig
 	config.ShanghaiTime = new(uint64)
 	config.CancunTime = new(uint64)
@@ -2460,6 +2463,8 @@ func TestFillBlobTransaction(t *testing.T) {
 	}
 	for _, tc := range suite {
 		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
 			res, err := api.FillTransaction(context.Background(), tc.args)
 			if len(tc.err) > 0 {
 				if err == nil {
diff --git a/internal/ethapi/transaction_args_test.go b/internal/ethapi/transaction_args_test.go
index 6750fc07a9..5317828173 100644
--- a/internal/ethapi/transaction_args_test.go
+++ b/internal/ethapi/transaction_args_test.go
@@ -42,6 +42,8 @@ import (
 
 // TestSetFeeDefaults tests the logic for filling in default fee values works as expected.
 func TestSetFeeDefaults(t *testing.T) {
+	t.Parallel()
+
 	type test struct {
 		name string
 		fork string // options: legacy, london, cancun
diff --git a/internal/flags/flags_test.go b/internal/flags/flags_test.go
index 681586b46c..cfe16b340e 100644
--- a/internal/flags/flags_test.go
+++ b/internal/flags/flags_test.go
@@ -24,6 +24,8 @@ import (
 )
 
 func TestPathExpansion(t *testing.T) {
+	t.Parallel()
+
 	user, _ := user.Current()
 	var tests map[string]string
 
@@ -53,9 +55,13 @@ func TestPathExpansion(t *testing.T) {
 
 	os.Setenv(`DDDXXX`, `/tmp`)
 	for test, expected := range tests {
-		got := expandPath(test)
-		if got != expected {
-			t.Errorf(`test %s, got %s, expected %s\n`, test, got, expected)
-		}
+		t.Run(test, func(t *testing.T) {
+			t.Parallel()
+
+			got := expandPath(test)
+			if got != expected {
+				t.Errorf(`test %s, got %s, expected %s\n`, test, got, expected)
+			}
+		})
 	}
 }
diff --git a/internal/guide/guide_test.go b/internal/guide/guide_test.go
index f682daac91..573898d7d0 100644
--- a/internal/guide/guide_test.go
+++ b/internal/guide/guide_test.go
@@ -35,6 +35,8 @@ import (
 
 // Tests that the account management snippets work correctly.
 func TestAccountManagement(t *testing.T) {
+	t.Parallel()
+
 	// Create a temporary folder to work with
 	workdir := t.TempDir()
 
diff --git a/internal/jsre/completion_test.go b/internal/jsre/completion_test.go
index 953bc5026d..8fbddbc299 100644
--- a/internal/jsre/completion_test.go
+++ b/internal/jsre/completion_test.go
@@ -23,6 +23,8 @@ import (
 )
 
 func TestCompleteKeywords(t *testing.T) {
+	t.Parallel()
+
 	re := New("", os.Stdout)
 	re.Run(`
 		function theClass() {
@@ -85,9 +87,13 @@ func TestCompleteKeywords(t *testing.T) {
 		},
 	}
 	for _, test := range tests {
-		cs := re.CompleteKeywords(test.input)
-		if !reflect.DeepEqual(cs, test.want) {
-			t.Errorf("wrong completions for %q\ngot  %v\nwant %v", test.input, cs, test.want)
-		}
+		t.Run(test.input, func(t *testing.T) {
+			t.Parallel()
+
+			cs := re.CompleteKeywords(test.input)
+			if !reflect.DeepEqual(cs, test.want) {
+				t.Errorf("wrong completions for %q\ngot  %v\nwant %v", test.input, cs, test.want)
+			}
+		})
 	}
 }
diff --git a/internal/jsre/jsre_test.go b/internal/jsre/jsre_test.go
index 18ef39e2f4..a812d6116d 100644
--- a/internal/jsre/jsre_test.go
+++ b/internal/jsre/jsre_test.go
@@ -51,6 +51,8 @@ func newWithTestJS(t *testing.T, testjs string) *JSRE {
 }
 
 func TestExec(t *testing.T) {
+	t.Parallel()
+
 	jsre := newWithTestJS(t, `msg = "testMsg"`)
 
 	err := jsre.Exec("test.js")
@@ -73,6 +75,8 @@ func TestExec(t *testing.T) {
 }
 
 func TestNatto(t *testing.T) {
+	t.Parallel()
+
 	jsre := newWithTestJS(t, `setTimeout(function(){msg = "testMsg"}, 1);`)
 
 	err := jsre.Exec("test.js")
@@ -96,6 +100,8 @@ func TestNatto(t *testing.T) {
 }
 
 func TestBind(t *testing.T) {
+	t.Parallel()
+
 	jsre := New("", os.Stdout)
 	defer jsre.Stop(false)
 
@@ -108,6 +114,8 @@ func TestBind(t *testing.T) {
 }
 
 func TestLoadScript(t *testing.T) {
+	t.Parallel()
+
 	jsre := newWithTestJS(t, `msg = "testMsg"`)
 
 	_, err := jsre.Run(`loadScript("test.js")`)
diff --git a/internal/utesting/utesting_test.go b/internal/utesting/utesting_test.go
index 31c7911c52..526d36bab1 100644
--- a/internal/utesting/utesting_test.go
+++ b/internal/utesting/utesting_test.go
@@ -24,6 +24,8 @@ import (
 )
 
 func TestTest(t *testing.T) {
+	t.Parallel()
+
 	tests := []Test{
 		{
 			Name: "successful test",
@@ -90,6 +92,8 @@ var outputTests = []Test{
 }
 
 func TestOutput(t *testing.T) {
+	t.Parallel()
+
 	var buf bytes.Buffer
 	RunTests(outputTests, &buf)
 
@@ -116,6 +120,8 @@ $`[1:])
 }
 
 func TestOutputTAP(t *testing.T) {
+	t.Parallel()
+
 	var buf bytes.Buffer
 	RunTAP(outputTests, &buf)