diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGSelectQueryBlock.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGSelectQueryBlock.java
index 42af9b171a..88b53b0e3c 100644
--- a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGSelectQueryBlock.java
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGSelectQueryBlock.java
@@ -55,7 +55,11 @@ public class PGSelectQueryBlock extends SQLSelectQueryBlock implements PGSQLObje
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {
-        accept0((PGASTVisitor) visitor);
+        if (visitor instanceof PGASTVisitor) {
+            accept0((PGASTVisitor) visitor);
+        } else {
+            super.accept0(visitor);
+        }
     }
 
     @Override
diff --git a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGSelectStatement.java b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGSelectStatement.java
index cecbc651ab..fc90479b32 100644
--- a/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGSelectStatement.java
+++ b/src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGSelectStatement.java
@@ -32,7 +32,11 @@ public class PGSelectStatement extends SQLSelectStatement implements PGSQLStatem
     }
 
     protected void accept0(SQLASTVisitor visitor) {
-        accept0((PGASTVisitor) visitor);
+        if (visitor instanceof PGASTVisitor) {
+            accept0((PGASTVisitor) visitor);
+        } else {
+            super.accept0(visitor);
+        }
     }
 
     public void accept0(PGASTVisitor visitor) {