diff --git a/Cargo.lock b/Cargo.lock
index 9cc34a876dc..ef0316f30fb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1494,9 +1494,9 @@ dependencies = [
 
 [[package]]
 name = "rustc-ap-rustc_lexer"
-version = "725.0.0"
+version = "727.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f950742ef8a203aa7661aad3ab880438ddeb7f95d4b837c30d65db1a2c5df68e"
+checksum = "8f40f26e7abdcd3b982f36c09a634cc6187988fbf6ec466c91f8d30a12ac0237"
 dependencies = [
  "unicode-xid",
 ]
diff --git a/crates/parser/Cargo.toml b/crates/parser/Cargo.toml
index ab48b1392a9..08359133f1a 100644
--- a/crates/parser/Cargo.toml
+++ b/crates/parser/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 
 [dependencies]
 drop_bomb = "0.1.5"
-rustc_lexer = { version = "725.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "727.0.0", package = "rustc-ap-rustc_lexer" }
 
 limit.workspace = true
 
diff --git a/crates/parser/src/lexed_str.rs b/crates/parser/src/lexed_str.rs
index b48921f1917..100deff462d 100644
--- a/crates/parser/src/lexed_str.rs
+++ b/crates/parser/src/lexed_str.rs
@@ -82,6 +82,7 @@ pub fn kind(&self, i: usize) -> SyntaxKind {
     pub fn text(&self, i: usize) -> &str {
         self.range_text(i..i + 1)
     }
+
     pub fn range_text(&self, r: ops::Range<usize>) -> &str {
         assert!(r.start < r.end && r.end <= self.len());
         let lo = self.start[r.start] as usize;
@@ -216,6 +217,10 @@ fn extend_token(&mut self, kind: &rustc_lexer::TokenKind, token_text: &str) {
                 rustc_lexer::TokenKind::Caret => T![^],
                 rustc_lexer::TokenKind::Percent => T![%],
                 rustc_lexer::TokenKind::Unknown => ERROR,
+                rustc_lexer::TokenKind::UnknownPrefix => {
+                    err = "unknown literal prefix";
+                    IDENT
+                }
             }
         };
 
diff --git a/crates/syntax/Cargo.toml b/crates/syntax/Cargo.toml
index 1a845a6ee71..8fc493a23f5 100644
--- a/crates/syntax/Cargo.toml
+++ b/crates/syntax/Cargo.toml
@@ -16,7 +16,7 @@ doctest = false
 cov-mark = "2.0.0-pre.1"
 itertools = "0.10.5"
 rowan = "0.15.10"
-rustc_lexer = { version = "725.0.0", package = "rustc-ap-rustc_lexer" }
+rustc_lexer = { version = "727.0.0", package = "rustc-ap-rustc_lexer" }
 rustc-hash = "1.1.0"
 once_cell = "1.17.0"
 indexmap = "1.9.1"