diff --git a/field_test.go b/field_test.go
index 7c1a1295f..59c516879 100644
--- a/field_test.go
+++ b/field_test.go
@@ -22,7 +22,6 @@ package zap
 
 import (
 	"errors"
-	"math"
 	"net"
 	"sync"
 	"testing"
@@ -32,11 +31,6 @@ import (
 	"go.uber.org/zap/zapcore"
 )
 
-var (
-	// Compiler complains about constants overflowing, so store this in a variable.
-	maxUint64 = uint64(math.MaxUint64)
-)
-
 type username string
 
 func (n username) MarshalLogObject(enc zapcore.ObjectEncoder) error {
diff --git a/zapcore/json_encoder.go b/zapcore/json_encoder.go
index 1dfc6a968..ce225dfc3 100644
--- a/zapcore/json_encoder.go
+++ b/zapcore/json_encoder.go
@@ -32,12 +32,8 @@ import (
 	"go.uber.org/zap/internal/bufferpool"
 )
 
-const (
-	// For JSON-escaping; see jsonEncoder.safeAddString below.
-	_hex = "0123456789abcdef"
-	// Initial buffer size for encoders.
-	_initialBufSize = 1024
-)
+// For JSON-escaping; see jsonEncoder.safeAddString below.
+const _hex = "0123456789abcdef"
 
 var _jsonPool = sync.Pool{New: func() interface{} {
 	return &jsonEncoder{}