diff --git a/CHANGELOG.md b/CHANGELOG.md
index 35b0fbe..f4c8605 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,8 @@
 * 2.1.next in progress
   * Fix #371 by treating the operand of `NOT` as a nested expression (so it is parenthesized unless it is a simple value).
   * Fix #370 by **always** parenthesizing the operand of `:nest`.
+  * Fix #354 by supporting `DROP COLUMN IF EXISTS` / `ADD COLUMN IF NOT EXISTS`.
+  * Update `build-clj` to v0.5.5.
 
 * 2.1.818 -- 2021-10-04
   * Fix #367 by supporting parameters in subexpressions around `IS NULL` / `IS NOT NULL` tests.
diff --git a/doc/clause-reference.md b/doc/clause-reference.md
index fa07044..16fa67e 100644
--- a/doc/clause-reference.md
+++ b/doc/clause-reference.md
@@ -43,9 +43,15 @@ If a single table name is provided, a single column
 user=> (sql/format {:alter-table :fruit
                     :add-column [:id :int [:not nil]]})
 ["ALTER TABLE fruit ADD COLUMN id INT NOT NULL"]
+user=> (sql/format {:alter-table :fruit
+                    :add-column [:id :int [:not nil] :if-not-exists]})
+["ALTER TABLE fruit ADD COLUMN IF NOT EXISTS id INT NOT NULL"]
 user=> (sql/format {:alter-table :fruit
                     :drop-column :ident})
 ["ALTER TABLE fruit DROP COLUMN ident"]
+user=> (sql/format {:alter-table :fruit
+                    :drop-column [:if-exists :ident]})
+["ALTER TABLE fruit DROP COLUMN IF EXISTS ident"]
 user=> (sql/format {:alter-table :fruit
                     :modify-column [:id :int :unsigned nil]})
 ["ALTER TABLE fruit MODIFY COLUMN id INT UNSIGNED NULL"]
@@ -63,6 +69,16 @@ user=> (sql/format {:alter-table [:fruit
                                   {:add-column [:id :int [:not nil]]}
                                   {:drop-column :ident}]})
 ["ALTER TABLE fruit ADD COLUMN id INT NOT NULL, DROP COLUMN ident"]
+user=> (sql/format {:alter-table [:fruit
+                                  {:add-column [:id :int [:not nil]]}
+                                  {:add-column [:name [:varchar 32]]}
+                                  {:drop-column :ident}
+                                  {:modify-column [:appearance :text]}]})
+["ALTER TABLE fruit ADD COLUMN id INT NOT NULL, ADD COLUMN name VARCHAR(32), DROP COLUMN ident, MODIFY COLUMN appearance TEXT"]
+user=> (sql/format {:alter-table [:fruit
+                                  {:add-column [:id :int [:not nil] :if-not-exists]}
+                                  {:drop-column [:if-exists :ident]}]})
+["ALTER TABLE fruit ADD COLUMN IF NOT EXISTS id INT NOT NULL, DROP COLUMN IF EXISTS ident"]
 ```
 
 As can be seen above, `:add-column` and `:modify-column`
diff --git a/src/honey/sql.cljc b/src/honey/sql.cljc
index b97a295..d347387 100644
--- a/src/honey/sql.cljc
+++ b/src/honey/sql.cljc
@@ -813,7 +813,9 @@
         ")")])
 
 (defn- format-add-item [k spec]
-  [(str (sql-kw k) " " (format-single-column spec))])
+  (if (contains? #{:if-not-exists 'if-not-exists} (last spec))
+    [(str (sql-kw k) " " (sql-kw :if-not-exists) " " (format-single-column (butlast spec)))]
+    [(str (sql-kw k) " " (format-single-column spec))]))
 
 (defn- format-rename-item [k [x y]]
   [(str (sql-kw k) " " (format-entity x) " TO " (format-entity y))])
@@ -849,7 +851,7 @@
   and removed."
   (atom {:alter-table     #'format-alter-table
          :add-column      #'format-add-item
-         :drop-column     #'format-selector
+         :drop-column     #'format-drop-items
          :modify-column   #'format-add-item
          :rename-column   #'format-rename-item
          ;; so :add-index works with both [:index] and [:unique]