diff --git a/jid/CHANGELOG.md b/jid/CHANGELOG.md
index 111cb8c..ef233e9 100644
--- a/jid/CHANGELOG.md
+++ b/jid/CHANGELOG.md
@@ -8,6 +8,7 @@ Unreleased
   * Additions
     - Parsing invalid JIDs with stringprep feature no longer results in panic,
     returning Error with NodePrep, NamePrep or ResourcePrep variant instead (#84)
+    - Parsing already-normalized JIDs with stringprep is much faster, about 20 times.
     - JID parts are now typed as NodePart, DomainPart and ResourcePart ; once part into those types,
     JID operations cannot fail
     - BareJid::with_resource appends a ResourcePart to a BareJid to produce a FullJid (#204)
diff --git a/jid/Cargo.toml b/jid/Cargo.toml
index 5758c64..63dea0d 100644
--- a/jid/Cargo.toml
+++ b/jid/Cargo.toml
@@ -22,4 +22,4 @@ gitlab = { repository = "xmpp-rs/xmpp-rs" }
 memchr = "2.5"
 minidom = { version = "0.15", optional = true }
 serde = { version = "1.0", features = ["derive"], optional = true }
-stringprep = "0.1.2"
+stringprep = "0.1.3"
diff --git a/jid/src/inner.rs b/jid/src/inner.rs
index e124b42..644e4c2 100644
--- a/jid/src/inner.rs
+++ b/jid/src/inner.rs
@@ -13,6 +13,7 @@
 use crate::Error;
 use core::num::NonZeroU16;
 use memchr::memchr;
+use std::borrow::Cow;
 use std::str::FromStr;
 use stringprep::{nameprep, nodeprep, resourceprep};
 
@@ -57,7 +58,12 @@ impl InnerJid {
 
                 orig_at = Some(node.len());
                 orig_slash = Some(node.len() + domain.len() + 1);
-                format!("{node}@{domain}/{resource}")
+                match (node, domain, resource) {
+                    (Cow::Borrowed(_), Cow::Borrowed(_), Cow::Borrowed(_)) => {
+                        unnormalized.to_string()
+                    }
+                    (node, domain, resource) => format!("{node}@{domain}/{resource}"),
+                }
             }
             (Some(at), None) => {
                 let node = nodeprep(&unnormalized[..at]).map_err(|_| Error::NodePrep)?;
@@ -67,7 +73,10 @@ impl InnerJid {
                 length_check(domain.len(), Error::DomainEmpty, Error::DomainTooLong)?;
 
                 orig_at = Some(node.len());
-                format!("{node}@{domain}")
+                match (node, domain) {
+                    (Cow::Borrowed(_), Cow::Borrowed(_)) => unnormalized.to_string(),
+                    (node, domain) => format!("{node}@{domain}"),
+                }
             }
             (None, Some(slash)) => {
                 let domain = nameprep(&unnormalized[..slash]).map_err(|_| Error::NamePrep)?;
@@ -78,7 +87,10 @@ impl InnerJid {
                 length_check(resource.len(), Error::ResourceEmpty, Error::ResourceTooLong)?;
 
                 orig_slash = Some(domain.len());
-                format!("{domain}/{resource}")
+                match (domain, resource) {
+                    (Cow::Borrowed(_), Cow::Borrowed(_)) => unnormalized.to_string(),
+                    (domain, resource) => format!("{domain}/{resource}"),
+                }
             }
             (None, None) => {
                 let domain = nameprep(unnormalized).map_err(|_| Error::NamePrep)?;