diff --git a/lisp/org.el b/lisp/org.el
index 20879685c..3d3aca2a6 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -9048,7 +9048,7 @@ keywords relative to each registered export backend."
   '("ARCHIVE:" "AUTHOR:" "BIBLIOGRAPHY:" "BIND:" "CATEGORY:" "CITE_EXPORT:"
     "COLUMNS:" "CREATOR:" "DATE:" "DESCRIPTION:" "DRAWERS:" "EMAIL:"
     "EXCLUDE_TAGS:" "FILETAGS:" "INCLUDE:" "INDEX:" "KEYWORDS:" "LANGUAGE:"
-    "MACRO:" "OPTIONS:" "PROPERTY:" "PRINT_BIBLIOGRAPHY" "PRIORITIES:"
+    "MACRO:" "OPTIONS:" "PROPERTY:" "PRINT_BIBLIOGRAPHY:" "PRIORITIES:"
     "SELECT_TAGS:" "SEQ_TODO:" "SETUPFILE:" "STARTUP:" "TAGS:" "TITLE:" "TODO:"
     "TYP_TODO:" "SELECT_TAGS:" "EXCLUDE_TAGS:" "EXPORT_FILE_NAME:"))
 
diff --git a/lisp/ox-md.el b/lisp/ox-md.el
index fa2beeb95..48a3e8387 100644
--- a/lisp/ox-md.el
+++ b/lisp/ox-md.el
@@ -452,7 +452,7 @@ a communication channel."
 					(org-list-parents-alist struct)))))
 			   "."))))
     (concat bullet
-	    (make-string (- 4 (length bullet)) ? )
+	    (make-string (max 1 (- 4 (length bullet))) ? )
 	    (pcase (org-element-property :checkbox item)
 	      (`on "[X] ")
 	      (`trans "[-] ")
diff --git a/testing/lisp/test-ox-md.el b/testing/lisp/test-ox-md.el
index bf3dced1b..550265fdf 100644
--- a/testing/lisp/test-ox-md.el
+++ b/testing/lisp/test-ox-md.el
@@ -39,5 +39,24 @@
         (goto-char (point-min))
         (should (search-forward "#### Footnotes"))))))
 
+(ert-deftest ox-md/item ()
+  "Test `org-md-item'."
+  ;; Align items at column 4.
+  ;; Columns >=100 not aligned.
+  (org-test-with-temp-text
+      (mapconcat
+       #'identity
+       (cl-loop for n from 1 to 105
+                collect (format "%d. item" n))
+       "\n")
+    (let ((export-buffer "*Test MD Export*")
+          (org-export-show-temporary-export-buffer nil))
+      (org-export-to-buffer 'md export-buffer)
+      (with-current-buffer export-buffer
+        (goto-char (point-min))
+        (should (search-forward "1.  item"))
+        (should (search-forward "10. item"))
+        (should (search-forward "101. item"))))))
+
 (provide 'test-ox-md)
 ;;; test-ox-md.el ends here