diff --git a/src/package.lisp b/src/package.lisp
index 57befea..1aa7217 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -35,6 +35,7 @@
   (:export #:apply-identifier-case
            #:build-identifier
            #:quoted-p
+           #:ensure-quoted
            #:ensure-unquoted
            #:camelCase-to-colname))
 
diff --git a/src/pgsql/pgsql-ddl.lisp b/src/pgsql/pgsql-ddl.lisp
index 4fe2316..a6f1b2a 100644
--- a/src/pgsql/pgsql-ddl.lisp
+++ b/src/pgsql/pgsql-ddl.lisp
@@ -144,7 +144,7 @@
                     (make-column :default transformed-default)))
               (format-default-value transformed-column))
             (if default
-                (format stream "'~a'" default)
+                (ensure-quoted default #\')
                 (format stream "NULL"))))))
 
 
diff --git a/src/utils/quoting.lisp b/src/utils/quoting.lisp
index f6cc05d..d52702d 100644
--- a/src/utils/quoting.lisp
+++ b/src/utils/quoting.lisp
@@ -7,11 +7,6 @@
 
 (in-package :pgloader.quoting)
 
-(defun quoted-p (s)
-  "Return true if s is a double-quoted string"
-  (and (eq (char s 0) #\")
-       (eq (char s (- (length s) 1)) #\")))
-
 (defun apply-identifier-case (identifier)
   "Return given IDENTIFIER with CASE handled to be PostgreSQL compatible."
   (let* ((lowercase-identifier (cl-ppcre:regex-replace-all
@@ -47,6 +42,11 @@
                            (cl-ppcre:regex-replace-all "\"" identifier "\"\"")))
       (:none       identifier))))
 
+(defun quoted-p (s &optional (quote-char #\"))
+  "Return true if s is a double-quoted string"
+  (and (eq (char s 0) quote-char)
+       (eq (char s (- (length s) 1)) quote-char)))
+
 (defun ensure-unquoted (identifier)
   (cond ((quoted-p identifier)
          ;; when the table name comes from the user (e.g. in the
@@ -57,6 +57,11 @@
 
         (t identifier)))
 
+(defun ensure-quoted (value &optional (quote-char #\"))
+  (if (quoted-p value quote-char)
+      value
+      (format nil "~c~a~c" quote-char value quote-char)))
+
 (defun build-identifier (sep &rest parts)
   "Concatenante PARTS into a PostgreSQL identifier, with SEP in between
    parts. That's useful for creating an index name from a table's oid and name."