diff --git a/src/honeysql/format.cljc b/src/honeysql/format.cljc
index 43b184e..d11ceee 100644
--- a/src/honeysql/format.cljc
+++ b/src/honeysql/format.cljc
@@ -560,13 +560,16 @@
   (str "WITH RECURSIVE " (comma-join (map cte->sql ctes))))
 
 (defmethod format-clause :union [[_ maps] _]
-  (string/join " UNION " (map to-sql maps)))
+  (binding [*subquery?* false]
+    (string/join " UNION " (map to-sql maps))))
 
 (defmethod format-clause :union-all [[_ maps] _]
-  (string/join " UNION ALL " (map to-sql maps)))
+  (binding [*subquery?* false]
+    (string/join " UNION ALL " (map to-sql maps))))
 
 (defmethod format-clause :intersect [[_ maps] _]
-  (string/join " INTERSECT " (map to-sql maps)))
+  (binding [*subquery?* false]
+    (string/join " INTERSECT " (map to-sql maps))))
 
 (defmethod fn-handler "case" [_ & clauses]
   (str "CASE "
diff --git a/test/honeysql/format_test.cljc b/test/honeysql/format_test.cljc
index 5338eea..e1083bc 100644
--- a/test/honeysql/format_test.cljc
+++ b/test/honeysql/format_test.cljc
@@ -77,16 +77,22 @@
          ["INSERT INTO foo (baz) VALUES (ARRAY[?, ?, ?])" "one" "two" "three"])))
 
 (deftest union-test
+  ;; UNION and INTERSECT subexpressions should not be parenthesized.
+  ;; If you need to add more complex expressions, use a subquery like this:
+  ;;   SELECT foo FROM bar1
+  ;;   UNION
+  ;;   SELECT foo FROM (SELECT foo FROM bar2 ORDER BY baz LIMIT 2)
+  ;;   ORDER BY foo ASC
   (is (= (format {:union [{:select [:foo] :from [:bar1]}
                           {:select [:foo] :from [:bar2]}]})
-         ["(SELECT foo FROM bar1) UNION (SELECT foo FROM bar2)"])))
+         ["SELECT foo FROM bar1 UNION SELECT foo FROM bar2"])))
 
 (deftest union-all-test
   (is (= (format {:union-all [{:select [:foo] :from [:bar1]}
                               {:select [:foo] :from [:bar2]}]})
-         ["(SELECT foo FROM bar1) UNION ALL (SELECT foo FROM bar2)"])))
+         ["SELECT foo FROM bar1 UNION ALL SELECT foo FROM bar2"])))
 
 (deftest intersect-test
   (is (= (format {:intersect [{:select [:foo] :from [:bar1]}
                               {:select [:foo] :from [:bar2]}]})
-         ["(SELECT foo FROM bar1) INTERSECT (SELECT foo FROM bar2)"])))
+         ["SELECT foo FROM bar1 INTERSECT SELECT foo FROM bar2"])))