diff --git a/parser/distsql/engine/src/main/java/org/apache/shardingsphere/distsql/parser/core/kernel/KernelDistSQLStatementVisitor.java b/parser/distsql/engine/src/main/java/org/apache/shardingsphere/distsql/parser/core/kernel/KernelDistSQLStatementVisitor.java
index 795f162297fe3..d0e2f69f7e01b 100644
--- a/parser/distsql/engine/src/main/java/org/apache/shardingsphere/distsql/parser/core/kernel/KernelDistSQLStatementVisitor.java
+++ b/parser/distsql/engine/src/main/java/org/apache/shardingsphere/distsql/parser/core/kernel/KernelDistSQLStatementVisitor.java
@@ -209,10 +209,8 @@ private Properties getProperties(final PropertiesDefinitionContext ctx) {
     
     @Override
     public ASTNode visitUnregisterStorageUnit(final UnregisterStorageUnitContext ctx) {
-        boolean ignoreSingleTables = null != ctx.ignoreTables() 
-                && (ctx.ignoreTables() instanceof IgnoreSingleAndBroadcastTablesContext || ctx.ignoreTables() instanceof IgnoreSingleTablesContext);
-        boolean ignoreBroadcastTables = null != ctx.ignoreTables() 
-                && (ctx.ignoreTables() instanceof IgnoreSingleAndBroadcastTablesContext || ctx.ignoreTables() instanceof IgnoreBroadcastTablesContext);
+        boolean ignoreSingleTables = ctx.ignoreTables() instanceof IgnoreSingleAndBroadcastTablesContext || ctx.ignoreTables() instanceof IgnoreSingleTablesContext;
+        boolean ignoreBroadcastTables = ctx.ignoreTables() instanceof IgnoreSingleAndBroadcastTablesContext || ctx.ignoreTables() instanceof IgnoreBroadcastTablesContext;
         return new UnregisterStorageUnitStatement(null != ctx.ifExists(),
                 ctx.storageUnitName().stream().map(ParseTree::getText).map(each -> new IdentifierValue(each).getValue()).collect(Collectors.toList()),
                 ignoreSingleTables, ignoreBroadcastTables);