diff --git a/src/domains.rs b/src/domains.rs
index 4585284..df281a6 100644
--- a/src/domains.rs
+++ b/src/domains.rs
@@ -203,7 +203,7 @@ pub(crate) fn find_authority_end(
 
 fn valid_tld(tld: &str) -> bool {
     tld.chars()
-        .take_while(|c| c.is_ascii_alphabetic())
+        .take_while(|c| c.is_ascii_alphanumeric())
         .take(2)
         .count()
         >= 2
diff --git a/tests/domains.rs b/tests/domains.rs
index f8c7f44..2535a60 100644
--- a/tests/domains.rs
+++ b/tests/domains.rs
@@ -191,3 +191,12 @@ fn assert_linked(input: &str, expected: &str) {
 fn assert_not_linked(s: &str) {
     assert_linked(s, s);
 }
+
+#[test]
+fn i2p_valid() {
+    assert_linked(
+        "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.b32.i2p",
+        "|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.b32.i2p|",
+    );
+    assert_linked("xxxx.i2p", "|xxxx.i2p|");
+}