diff --git a/partiql-ast/src/main/kotlin/org/partiql/ast/sql/SqlDialect.kt b/partiql-ast/src/main/kotlin/org/partiql/ast/sql/SqlDialect.kt
index 6a589a0556..c4ad9217fc 100644
--- a/partiql-ast/src/main/kotlin/org/partiql/ast/sql/SqlDialect.kt
+++ b/partiql-ast/src/main/kotlin/org/partiql/ast/sql/SqlDialect.kt
@@ -64,6 +64,13 @@ public abstract class SqlDialect : AstBaseVisitor<SqlBlock, SqlBlock>() {
             h = h concat ")"
             h
         }
+        is Expr.BagOp -> {
+            var h = head
+            h = h concat "("
+            h = visitExprBagOp(node, h)
+            h = h concat ")"
+            h
+        }
         else -> visitExpr(node, head)
     }
 
diff --git a/partiql-ast/src/main/kotlin/org/partiql/ast/sql/internal/InternalSqlDialect.kt b/partiql-ast/src/main/kotlin/org/partiql/ast/sql/internal/InternalSqlDialect.kt
index 4ecfb9d569..4612feefeb 100644
--- a/partiql-ast/src/main/kotlin/org/partiql/ast/sql/internal/InternalSqlDialect.kt
+++ b/partiql-ast/src/main/kotlin/org/partiql/ast/sql/internal/InternalSqlDialect.kt
@@ -82,6 +82,13 @@ internal abstract class InternalSqlDialect : AstBaseVisitor<InternalSqlBlock, In
             t = t concat ")"
             t
         }
+        is Expr.BagOp -> {
+            var t = tail
+            t = t concat "("
+            t = visitExprBagOp(node, t)
+            t = t concat ")"
+            t
+        }
         else -> visitExpr(node, tail)
     }
 
diff --git a/partiql-ast/src/test/kotlin/org/partiql/ast/sql/SqlDialectTest.kt b/partiql-ast/src/test/kotlin/org/partiql/ast/sql/SqlDialectTest.kt
index 6276adb43d..9520d83519 100644
--- a/partiql-ast/src/test/kotlin/org/partiql/ast/sql/SqlDialectTest.kt
+++ b/partiql-ast/src/test/kotlin/org/partiql/ast/sql/SqlDialectTest.kt
@@ -986,6 +986,120 @@ class SqlDialectTest {
                     rhs = v("y")
                 }
             },
+            expect("(x UNION y) UNION z") {
+                exprBagOp {
+                    type = setOp {
+                        type = SetOp.Type.UNION
+                        setq = null
+                    }
+                    outer = false
+                    lhs = exprBagOp {
+                        type = setOp {
+                            type = SetOp.Type.UNION
+                            setq = null
+                        }
+                        outer = false
+                        lhs = v("x")
+                        rhs = v("y")
+                    }
+                    rhs = v("z")
+                }
+            },
+            expect("x UNION (y UNION z)") {
+                exprBagOp {
+                    type = setOp {
+                        type = SetOp.Type.UNION
+                        setq = null
+                    }
+                    outer = false
+                    lhs = v("x")
+                    rhs = exprBagOp {
+                        type = setOp {
+                            type = SetOp.Type.UNION
+                            setq = null
+                        }
+                        outer = false
+                        lhs = v("y")
+                        rhs = v("z")
+                    }
+                }
+            },
+            expect("(x EXCEPT y) EXCEPT z") {
+                exprBagOp {
+                    type = setOp {
+                        type = SetOp.Type.EXCEPT
+                        setq = null
+                    }
+                    outer = false
+                    lhs = exprBagOp {
+                        type = setOp {
+                            type = SetOp.Type.EXCEPT
+                            setq = null
+                        }
+                        outer = false
+                        lhs = v("x")
+                        rhs = v("y")
+                    }
+                    rhs = v("z")
+                }
+            },
+            expect("x EXCEPT (y EXCEPT z)") {
+                exprBagOp {
+                    type = setOp {
+                        type = SetOp.Type.EXCEPT
+                        setq = null
+                    }
+                    outer = false
+                    lhs = v("x")
+                    rhs = exprBagOp {
+                        type = setOp {
+                            type = SetOp.Type.EXCEPT
+                            setq = null
+                        }
+                        outer = false
+                        lhs = v("y")
+                        rhs = v("z")
+                    }
+                }
+            },
+            expect("(x INTERSECT y) INTERSECT z") {
+                exprBagOp {
+                    type = setOp {
+                        type = SetOp.Type.INTERSECT
+                        setq = null
+                    }
+                    outer = false
+                    lhs = exprBagOp {
+                        type = setOp {
+                            type = SetOp.Type.INTERSECT
+                            setq = null
+                        }
+                        outer = false
+                        lhs = v("x")
+                        rhs = v("y")
+                    }
+                    rhs = v("z")
+                }
+            },
+            expect("x INTERSECT (y INTERSECT z)") {
+                exprBagOp {
+                    type = setOp {
+                        type = SetOp.Type.INTERSECT
+                        setq = null
+                    }
+                    outer = false
+                    lhs = v("x")
+                    rhs = exprBagOp {
+                        type = setOp {
+                            type = SetOp.Type.INTERSECT
+                            setq = null
+                        }
+                        outer = false
+                        lhs = v("y")
+                        rhs = v("z")
+                    }
+                }
+            },
         )
 
         @JvmStatic