diff --git a/openpgp-card/src/card_do.rs b/openpgp-card/src/card_do.rs
index 9a72d7b..7813aaa 100644
--- a/openpgp-card/src/card_do.rs
+++ b/openpgp-card/src/card_do.rs
@@ -311,7 +311,7 @@ impl Display for UIF {
 
 /// User interaction setting.
 ///
-/// See spec pg 24 and https://github.com/Yubico/yubikey-manager/blob/main/ykman/openpgp.py
+/// See spec pg 24 and <https://github.com/Yubico/yubikey-manager/blob/main/ykman/openpgp.py>
 #[non_exhaustive]
 pub enum TouchPolicy {
     Off,
@@ -759,7 +759,7 @@ impl Display for CardholderRelatedData {
 }
 
 /// 4.4.3.5 Sex
-/// Encoded in accordance with https://en.wikipedia.org/wiki/ISO/IEC_5218
+/// Encoded in accordance with <https://en.wikipedia.org/wiki/ISO/IEC_5218>
 #[derive(Debug, PartialEq, Clone, Copy)]
 pub enum Sex {
     NotKnown,
diff --git a/openpgp-card/src/card_do/application_id.rs b/openpgp-card/src/card_do/application_id.rs
index 54fb05c..6bf7a90 100644
--- a/openpgp-card/src/card_do/application_id.rs
+++ b/openpgp-card/src/card_do/application_id.rs
@@ -55,7 +55,7 @@ impl ApplicationIdentifier {
     }
 
     /// Mapping of manufacturer id to a name, data from:
-    /// https://en.wikipedia.org/wiki/OpenPGP_card [2022-04-07]
+    /// <https://en.wikipedia.org/wiki/OpenPGP_card> [2022-04-07]
     pub fn manufacturer_name(&self) -> &'static str {
         match self.manufacturer {
             0x0000 => "Testcard",
diff --git a/openpgp-card/src/tlv/tag.rs b/openpgp-card/src/tlv/tag.rs
index 620f556..84b3de2 100644
--- a/openpgp-card/src/tlv/tag.rs
+++ b/openpgp-card/src/tlv/tag.rs
@@ -8,7 +8,7 @@
 //!
 //! (The `ShortTag` type models tags that are exactly 1 or 2 octets long)
 //!
-//! https://en.wikipedia.org/wiki/X.690#Encoding
+//! <https://en.wikipedia.org/wiki/X.690#Encoding>
 
 use nom::{branch, bytes::complete as bytes, combinator, number::complete as number, sequence};