diff --git a/lib/foodsoft_article_import.rb b/lib/foodsoft_article_import.rb
index 22de3ee..7592b26 100644
--- a/lib/foodsoft_article_import.rb
+++ b/lib/foodsoft_article_import.rb
@@ -70,7 +70,7 @@ module FoodsoftArticleImport
     opts[:csv_options][:encoding] = encoding if encoding
     opts[:csv_options][:col_sep] = col_sep if col_sep
     opts[:csv_options][:liberal_parsing] = true if liberal_parsing
-    opts[:extension] = File.extname(filename) if filename
+    opts[:extension] = File.extname.File.basename(filename) if filename
     begin
       Roo::Spreadsheet.open(file, **opts)
     rescue StandardError => e