diff --git a/tabulate/__init__.py b/tabulate/__init__.py
index 11bb865..03eb3c3 100644
--- a/tabulate/__init__.py
+++ b/tabulate/__init__.py
@@ -224,7 +224,7 @@ def make_header_line(is_header, colwidths, colaligns):
             colwidths, [alignment[colalign] for colalign in colaligns]
         )
         asciidoc_column_specifiers = [
-            "{:d}{}".format(width, align) for width, align in asciidoc_alignments
+            "{}{:d}".format(align, width) for width, align in asciidoc_alignments
         ]
         header_list = ['cols="' + (",".join(asciidoc_column_specifiers)) + '"']