diff --git a/tabulate/__init__.py b/tabulate/__init__.py
index e100c09..f407317 100644
--- a/tabulate/__init__.py
+++ b/tabulate/__init__.py
@@ -295,7 +295,7 @@ def make_header_line(is_header, colwidths, colaligns):
 
     else:
         raise ValueError(
-            " _asciidoc_row() requires two (colwidths, colaligns) "
+            "_asciidoc_row() requires two (colwidths, colaligns) "
             + "or three (cell_values, colwidths, colaligns) arguments) "
         )