diff --git a/src/package.lisp b/src/package.lisp
index 68af7bc..8d15316 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -87,6 +87,8 @@
            #:add-field
            #:add-column
            #:add-index
+           #:find-index
+           #:maybe-add-index
            #:add-fkey
            #:find-fkey
            #:maybe-add-fkey
@@ -249,6 +251,8 @@
            #:add-field
            #:add-column
            #:add-index
+           #:find-index
+           #:maybe-add-index
            #:add-fkey
            #:find-fkey
            #:maybe-add-fkey
diff --git a/src/sources/mssql/mssql-schema.lisp b/src/sources/mssql/mssql-schema.lisp
index 9871b14..da49202 100644
--- a/src/sources/mssql/mssql-schema.lisp
+++ b/src/sources/mssql/mssql-schema.lisp
@@ -196,11 +196,13 @@ order by SchemaName,
      :do
      (let* ((schema     (find-schema catalog schema-name))
             (table      (find-table schema table-name))
-            (index      (make-pgsql-index :name index-name
+            (pg-index   (make-pgsql-index :name index-name
                                           :primary (= pkey 1)
                                           :unique (= unique 1)
-                                          :columns (list col))))
-       (add-index table index))
+                                          :columns nil))
+            (index      (maybe-add-index table index-name pg-index
+                                         :key #'pgloader.pgsql::pgsql-index-name)))
+       (push-to-end col (pgloader.pgsql::pgsql-index-columns index)))
      :finally (return catalog)))
 
 (defun list-all-fkeys (catalog &key including excluding)
diff --git a/src/utils/schema-structs.lisp b/src/utils/schema-structs.lisp
index 32a605a..0c4f7dc 100644
--- a/src/utils/schema-structs.lisp
+++ b/src/utils/schema-structs.lisp
@@ -77,9 +77,13 @@
   (:documentation
    "Find a table by TABLE-NAME in a schema OBJECT and return the table"))
 
+(defgeneric find-index (object index-name &key key test)
+  (:documentation
+   "Find an index by INDEX-NAME in a table OBJECT and return the index"))
+
 (defgeneric find-fkey (object fkey-name &key key test)
   (:documentation
-   "Find a table by FKEY-NAME in a table OBJECT and return the fkey"))
+   "Find a foreign key by FKEY-NAME in a table OBJECT and return the fkey"))
 
 (defgeneric maybe-add-schema (object schema-name &key)
   (:documentation "Add a new schema or return existing one."))
@@ -90,6 +94,9 @@
 (defgeneric maybe-add-view (object view-name &key)
   (:documentation "Add a new view or return existing one."))
 
+(defgeneric maybe-add-index (object index-name index &key key test)
+  (:documentation "Add a new index or return existing one."))
+
 (defgeneric maybe-add-fkey (object fkey-name fkey &key key test)
   (:documentation "Add a new fkey or return existing one."))
 
@@ -231,19 +238,29 @@
   (loop :for schema :in (catalog-schema-list catalog)
      :do (cast schema)))
 
+;;;
+;;; There's no simple equivalent to array_agg() in MS SQL, so the index and
+;;; fkey queries return a row per index|fkey column rather than per
+;;; index|fkey. Hence this extra API:
+;;;
 (defmethod add-index ((table table) index &key)
   "Add INDEX to TABLE and return the TABLE."
   (push-to-end index (table-index-list table)))
 
+(defmethod find-index ((table table) index-name &key key (test #'string=))
+  "Find INDEX-NAME in TABLE and return the INDEX object of this name."
+  (find index-name (table-index-list table) :key key :test test))
+
+(defmethod maybe-add-index ((table table) index-name index &key key (test #'string=))
+  "Add the index INDEX to the table-index-list of TABLE unless it already
+   exists, and return the INDEX object."
+  (let ((current-index (find-index table index-name :key key :test test)))
+    (or current-index (add-index table index))))
+
 (defmethod add-fkey ((table table) fkey &key)
   "Add FKEY to TABLE and return the TABLE."
   (push-to-end fkey (table-fkey-list table)))
 
-;;;
-;;; There's no simple equivalent to array_agg() in MS SQL, so the fkey query
-;;; returns a row per fkey column rather than per fkey. Hence this extra
-;;; API:
-;;;
 (defmethod find-fkey ((table table) fkey-name &key key (test #'string=))
   "Find FKEY-NAME in TABLE and return the FKEY object of this name."
   (find fkey-name (table-fkey-list table) :key key :test test))