diff --git a/common/bytes_test.go b/common/bytes_test.go
index 97dd34d159..7cf6553377 100644
--- a/common/bytes_test.go
+++ b/common/bytes_test.go
@@ -19,41 +19,43 @@ package common
 import (
 	"bytes"
 	"testing"
-
-	checker "gopkg.in/check.v1"
 )
 
-type BytesSuite struct{}
-
-var _ = checker.Suite(&BytesSuite{})
+func TestCopyBytes(t *testing.T) {
+	input := []byte{1, 2, 3, 4}
 
-func (s *BytesSuite) TestCopyBytes(c *checker.C) {
-	data1 := []byte{1, 2, 3, 4}
-	exp1 := []byte{1, 2, 3, 4}
-	res1 := CopyBytes(data1)
-	c.Assert(res1, checker.DeepEquals, exp1)
+	v := CopyBytes(input)
+	if !bytes.Equal(v, []byte{1, 2, 3, 4}) {
+		t.Fatal("not equal after copy")
+	}
+	v[0] = 99
+	if bytes.Equal(v, input) {
+		t.Fatal("result is not a copy")
+	}
 }
 
-func (s *BytesSuite) TestLeftPadBytes(c *checker.C) {
-	val1 := []byte{1, 2, 3, 4}
-	exp1 := []byte{0, 0, 0, 0, 1, 2, 3, 4}
-
-	res1 := LeftPadBytes(val1, 8)
-	res2 := LeftPadBytes(val1, 2)
+func TestLeftPadBytes(t *testing.T) {
+	val := []byte{1, 2, 3, 4}
+	padded := []byte{0, 0, 0, 0, 1, 2, 3, 4}
 
-	c.Assert(res1, checker.DeepEquals, exp1)
-	c.Assert(res2, checker.DeepEquals, val1)
+	if r := LeftPadBytes(val, 8); !bytes.Equal(r, padded) {
+		t.Fatalf("LeftPadBytes(%v, 8) == %v", val, r)
+	}
+	if r := LeftPadBytes(val, 2); !bytes.Equal(r, val) {
+		t.Fatalf("LeftPadBytes(%v, 2) == %v", val, r)
+	}
 }
 
-func (s *BytesSuite) TestRightPadBytes(c *checker.C) {
+func TestRightPadBytes(t *testing.T) {
 	val := []byte{1, 2, 3, 4}
-	exp := []byte{1, 2, 3, 4, 0, 0, 0, 0}
-
-	resstd := RightPadBytes(val, 8)
-	resshrt := RightPadBytes(val, 2)
+	padded := []byte{1, 2, 3, 4, 0, 0, 0, 0}
 
-	c.Assert(resstd, checker.DeepEquals, exp)
-	c.Assert(resshrt, checker.DeepEquals, val)
+	if r := RightPadBytes(val, 8); !bytes.Equal(r, padded) {
+		t.Fatalf("RightPadBytes(%v, 8) == %v", val, r)
+	}
+	if r := RightPadBytes(val, 2); !bytes.Equal(r, val) {
+		t.Fatalf("RightPadBytes(%v, 2) == %v", val, r)
+	}
 }
 
 func TestFromHex(t *testing.T) {
diff --git a/common/main_test.go b/common/main_test.go
deleted file mode 100644
index 149d09928a..0000000000
--- a/common/main_test.go
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2014 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package common
-
-import (
-	"testing"
-
-	checker "gopkg.in/check.v1"
-)
-
-func Test(t *testing.T) { checker.TestingT(t) }
diff --git a/common/types.go b/common/types.go
index 8ca51a05f8..cdcc6c20ad 100644
--- a/common/types.go
+++ b/common/types.go
@@ -20,6 +20,7 @@ import (
 	"database/sql/driver"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"math/big"
 	"math/rand"
@@ -142,7 +143,7 @@ func (h Hash) Value() (driver.Value, error) {
 }
 
 // ImplementsGraphQLType returns true if Hash implements the specified GraphQL type.
-func (_ Hash) ImplementsGraphQLType(name string) bool { return name == "Bytes32" }
+func (Hash) ImplementsGraphQLType(name string) bool { return name == "Bytes32" }
 
 // UnmarshalGraphQL unmarshals the provided GraphQL query data.
 func (h *Hash) UnmarshalGraphQL(input interface{}) error {
@@ -151,7 +152,7 @@ func (h *Hash) UnmarshalGraphQL(input interface{}) error {
 	case string:
 		err = h.UnmarshalText([]byte(input))
 	default:
-		err = fmt.Errorf("Unexpected type for Bytes32: %v", input)
+		err = fmt.Errorf("unexpected type %T for Hash", input)
 	}
 	return err
 }
@@ -290,7 +291,7 @@ func (a *Address) UnmarshalGraphQL(input interface{}) error {
 	case string:
 		err = a.UnmarshalText([]byte(input))
 	default:
-		err = fmt.Errorf("Unexpected type for Address: %v", input)
+		err = fmt.Errorf("unexpected type %T for Address", input)
 	}
 	return err
 }
@@ -323,7 +324,7 @@ func NewMixedcaseAddress(addr Address) MixedcaseAddress {
 // NewMixedcaseAddressFromString is mainly meant for unit-testing
 func NewMixedcaseAddressFromString(hexaddr string) (*MixedcaseAddress, error) {
 	if !IsHexAddress(hexaddr) {
-		return nil, fmt.Errorf("Invalid address")
+		return nil, errors.New("invalid address")
 	}
 	a := FromHex(hexaddr)
 	return &MixedcaseAddress{addr: BytesToAddress(a), original: hexaddr}, nil