diff --git a/table_schema_to_md.py b/table_schema_to_md.py
index 197d7f360ee1bdd25239d6494407d83b53897408..4744abc9a11daa1371bd8e32a5ad1d2e162f530c 100755
--- a/table_schema_to_md.py
+++ b/table_schema_to_md.py
@@ -90,7 +90,7 @@ def format_description(description):
 
 def format_format(format_val):
     """ Return markdown format information """
-    return "- `{}` {}\n".format(format_val, FORMAT_MAP[format_val])
+    return "- `{}` {}\n".format(format_val, FORMAT_MAP.get(format_val, ''))
 
 
 def format_type_specific_info(col_content):