diff --git a/pkg/expression/contextstatic/exprctx.go b/pkg/expression/contextstatic/exprctx.go
index af6d903b2232e..f6adac24c4436 100644
--- a/pkg/expression/contextstatic/exprctx.go
+++ b/pkg/expression/contextstatic/exprctx.go
@@ -162,7 +162,7 @@ func NewStaticExprContext(opts ...StaticExprCtxOption) *StaticExprContext {
 		staticExprCtxState: staticExprCtxState{
 			charset:                    cs.Name,
 			collation:                  cs.DefaultCollation,
-			defaultCollationForUTF8MB4: variable.DefaultCollationForUTF8MB4,
+			defaultCollationForUTF8MB4: mysql.DefaultCollationName,
 			blockEncryptionMode:        variable.DefBlockEncryptionMode,
 			sysDateIsNow:               variable.DefSysdateIsNow,
 			noopFuncsMode:              variable.TiDBOptOnOffWarn(variable.DefTiDBEnableNoopFuncs),
diff --git a/pkg/expression/contextstatic/exprctx_test.go b/pkg/expression/contextstatic/exprctx_test.go
index 0924ef73a4f1a..fa358402f1ed3 100644
--- a/pkg/expression/contextstatic/exprctx_test.go
+++ b/pkg/expression/contextstatic/exprctx_test.go
@@ -70,7 +70,7 @@ func checkDefaultStaticExprCtx(t *testing.T, ctx *StaticExprContext) {
 	require.NoError(t, err)
 	require.Equal(t, charsetName, cs.Name)
 	require.Equal(t, cs.DefaultCollation, collation)
-	require.Equal(t, variable.DefaultCollationForUTF8MB4, ctx.GetDefaultCollationForUTF8MB4())
+	require.Equal(t, mysql.DefaultCollationName, ctx.GetDefaultCollationForUTF8MB4())
 	require.Equal(t, variable.DefBlockEncryptionMode, ctx.GetBlockEncryptionMode())
 	require.Equal(t, variable.DefSysdateIsNow, ctx.GetSysdateIsNow())
 	require.Equal(t, variable.TiDBOptOnOffWarn(variable.DefTiDBEnableNoopFuncs), ctx.GetNoopFuncsMode())