diff --git a/lib/feed_reader/formats/rss.ex b/lib/feed_reader/formats/rss.ex
index bc56bc6..6092ace 100644
--- a/lib/feed_reader/formats/rss.ex
+++ b/lib/feed_reader/formats/rss.ex
@@ -11,7 +11,7 @@ defmodule FeedReader.Formats.RSS do
       [attributes] ->
         not Regex.match?(~r/\bversion\s*=/is, attributes) or
           Regex.match?(
-            ~r/\bversion\s*=\s*(["'])(?:0\.9(?:1|2)?|2\.0)\1/is,
+            ~r/\bversion\s*=\s*(["'])(?:0\.9(?:1|2)?|1\.0|2\.0)\1/is,
             attributes
           )
 
diff --git a/test/feed_reader/format_detection_test.exs b/test/feed_reader/format_detection_test.exs
index f922cb8..a8aa412 100644
--- a/test/feed_reader/format_detection_test.exs
+++ b/test/feed_reader/format_detection_test.exs
@@ -6,8 +6,8 @@ defmodule FeedReader.FormatDetectionTest do
   test "detects RSS, Atom, and RDF from a bounded XML prefix" do
     assert FeedReader.detect_format("<?xml version='1.0'?><rss version='2.0'>") == :rss
     assert FeedReader.detect_format("<rss version='0.91'>") == :rss
+    assert FeedReader.detect_format("<rss version='1.0'>") == :rss
     assert FeedReader.detect_format("<rss xmlns:xsi='urn:test'>") == :rss
-    assert FeedReader.detect_format("<rss version='1.0'>") == :unknown
     assert FeedReader.detect_format("<feed xmlns='http://www.w3.org/2005/Atom'>") == :atom
     assert FeedReader.detect_format("<rdf:RDF xmlns:rdf='urn:rdf'>") == :rdf
     assert FeedReader.detect_format("<html><body>not a feed</body></html>") == :unknown