diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d7441115..b93389e6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,6 +9,7 @@ on:
 
 env:
   RUSTFLAGS: -D warnings
+  RUSTDOCFLAGS: -D warnings
 
 jobs:
   rustfmt:
diff --git a/src/lib.rs b/src/lib.rs
index 4f490579..71c1465e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -353,7 +353,7 @@ impl DnType {
 pub enum DnValue {
     /// A string of characters from the T.61 character set
     TeletexString(Vec<u8>),
-    /// An ASCII string containing only A-Z, a-z, 0-9, '()+,-./:=? and <SPACE>
+    /// An ASCII string containing only A-Z, a-z, 0-9, '()+,-./:=? and `<SPACE>`
     PrintableString(String),
     /// A string encoded using UTF-32
     UniversalString(Vec<u8>),