diff --git a/cmd/utils/history_test.go b/cmd/utils/history_test.go
index 0f59762527..69256aaf01 100644
--- a/cmd/utils/history_test.go
+++ b/cmd/utils/history_test.go
@@ -157,7 +157,6 @@ func TestHistoryImportAndExport(t *testing.T) {
 					t.Fatalf("receipt root %d mismatch: want %s, got %s", n, want.ReceiptHash(), got)
 				}
 			}
-			return
 		}()
 	}
 
diff --git a/internal/era/e2store/e2store_test.go b/internal/era/e2store/e2store_test.go
index 64f4320f91..6e7b7fd37c 100644
--- a/internal/era/e2store/e2store_test.go
+++ b/internal/era/e2store/e2store_test.go
@@ -26,7 +26,7 @@ import (
 )
 
 func TestEncode(t *testing.T) {
-	for _, tt := range []struct {
+	for _, test := range []struct {
 		entries []Entry
 		want    string
 		name    string
@@ -50,6 +50,7 @@ func TestEncode(t *testing.T) {
 			want: "2a00020000000000beef0900040000000000abcdabcd",
 		},
 	} {
+		tt := test
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
 			var (
diff --git a/internal/era/era.go b/internal/era/era.go
index 3affe0e0e7..a369f947b8 100644
--- a/internal/era/era.go
+++ b/internal/era/era.go
@@ -143,6 +143,10 @@ func (e *Era) GetBlockByNumber(num uint64) (*types.Block, error) {
 		return nil, err
 	}
 	off += int64(n)
+	r, _, err = newSnappyReader(e.s, off)
+	if err != nil {
+		return nil, err
+	}
 	var body types.Body
 	if err := rlp.Decode(r, &body); err != nil {
 		return nil, err
@@ -193,7 +197,7 @@ func (e *Era) InitialTD() (*big.Int, error) {
 	}
 
 	// Read total difficulty after first block.
-	if r, n, err = newReader(e.s, off); err != nil {
+	if r, _, err = newReader(e.s, off); err != nil {
 		return nil, err
 	}
 	if err := rlp.Decode(r, rawTd); err != nil {
diff --git a/internal/era/iterator.go b/internal/era/iterator.go
index 3cc57a85e1..a9ac9f3d11 100644
--- a/internal/era/iterator.go
+++ b/internal/era/iterator.go
@@ -101,10 +101,9 @@ func (it *Iterator) TotalDifficulty() (*big.Int, error) {
 
 // RawIterator reads an RLP-encode Era1 entries.
 type RawIterator struct {
-	e         *Era   // backing Era1
-	curOffset int64  // offset of current block
-	next      uint64 // next block to read
-	err       error  // last error
+	e    *Era   // backing Era1
+	next uint64 // next block to read
+	err  error  // last error
 
 	Header          io.Reader
 	Body            io.Reader
@@ -143,7 +142,7 @@ func (it *RawIterator) Next() bool {
 		return true
 	}
 	off += int64(n)
-	if it.TotalDifficulty, n, it.err = newReader(it.e.s, off); it.err != nil {
+	if it.TotalDifficulty, _, it.err = newReader(it.e.s, off); it.err != nil {
 		return true
 	}
 	it.next += 1