diff --git a/CHANGELOG.md b/CHANGELOG.md
index b153302..ae35890 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # Changes
 
 * 2.6.next in progress
+  * Fix [#528](https://github.com/seancorfield/honeysql/issues/528) by preventing the `?` -> `??` escaping in SQL keywords just for operators.
   * Address [#527](https://github.com/seancorfield/honeysql/issues/527) by adding tests and more documentation for `:composite`.
   * Update Clojure versions (to 1.11.2 and 1.12.0-alpha9).
 
diff --git a/src/honey/sql.cljc b/src/honey/sql.cljc
index 1d09d33..88a9b81 100644
--- a/src/honey/sql.cljc
+++ b/src/honey/sql.cljc
@@ -326,6 +326,27 @@
         [v a d (format-entity v {:aliased a :drop-ns d})])))
   )
 
+(defn sql-op-kw
+  "Given a keyword for an operator, return a SQL representation of it as a string.
+
+  A keyword whose name begins with a single quote is left exactly as-is
+  (with the `:` and `'` removed), otherwise a `:kebab-case` keyword
+  becomes a `KEBAB CASE` (uppercase) string with hyphens replaced
+  by spaces, e.g., `:insert-into` => `INSERT INTO`.
+
+  Any namespace qualifier is ignored.
+
+  Unlike sql-kw below, ? is NOT escaped to ??."
+  [k]
+  (when k
+    (let [n (name k)]
+      (if (= \' (first n))
+        (let [ident   (subs n 1)
+              ident-l (str/lower-case ident)]
+          (binding [*quoted* (when-not (contains? #{"array"} ident-l) *quoted*)]
+            (format-entity (keyword ident))))
+        (-> n (dehyphen) (upper-case))))))
+
 (defn sql-kw
   "Given a keyword, return a SQL representation of it as a string.
 
@@ -1943,10 +1964,10 @@
     (when-not (pos? (count sqls))
       (throw (ex-info (str "no operands found for " op')
                       {:expr expr})))
-    (into [(cond-> (str/join (str " " (sql-kw op) " ") sqls)
+    (into [(cond-> (str/join (str " " (sql-op-kw op) " ") sqls)
              (and (contains? @op-can-be-unary op)
                   (= 1 (count sqls)))
-             (as-> s (str (sql-kw op) " " s))
+             (as-> s (str (sql-op-kw op) " " s))
              nested
              (as-> s (str "(" s ")")))]
           params)))
diff --git a/test/honey/sql/pg_ops_test.cljc b/test/honey/sql/pg_ops_test.cljc
index a310b79..e030a80 100644
--- a/test/honey/sql/pg_ops_test.cljc
+++ b/test/honey/sql/pg_ops_test.cljc
@@ -20,11 +20,11 @@
            (sql/format {:select [[[:#> :a :b] :x]]})))
     (is (= ["SELECT a #>> b AS x"]
            (sql/format {:select [[[:#>> :a :b] :x]]})))
-    (is (= ["SELECT a ?? b AS x"]
+    (is (= ["SELECT a ? b AS x"]
            (sql/format {:select [[[:? :a :b] :x]]})))
-    (is (= ["SELECT a ??| b AS x"]
+    (is (= ["SELECT a ?| b AS x"]
            (sql/format {:select [[[:?| :a :b] :x]]})))
-    (is (= ["SELECT a ??& b AS x"]
+    (is (= ["SELECT a ?& b AS x"]
            (sql/format {:select [[[:?& :a :b] :x]]})))
     (is (= ["SELECT a #- b AS x"]
            (sql/format {:select [[[:#- :a :b] :x]]}))))
@@ -33,7 +33,7 @@
            (sql/format {:select [[[sut/at> :a :b] :x]]})))
     (is (= ["SELECT a <@ b AS x"]
            (sql/format {:select [[[sut/<at :a :b] :x]]})))
-    (is (= ["SELECT a @?? b AS x"]
+    (is (= ["SELECT a @? b AS x"]
            (sql/format {:select [[[sut/at? :a :b] :x]]})))
     (is (= ["SELECT a @@ b AS x"]
            (sql/format {:select [[[sut/atat :a :b] :x]]}))))