diff --git a/lib/src/fileset.pest b/lib/src/fileset.pest
index 83e17780cc..c06a2ce73f 100644
--- a/lib/src/fileset.pest
+++ b/lib/src/fileset.pest
@@ -14,10 +14,17 @@
 
 whitespace = _{ " " | "\t" | "\r" | "\n" | "\x0c" }
 
-// TODO: adjust identifier rule for file names
-identifier_part = @{ (ASCII_ALPHANUMERIC | "_" | "/")+ }
+// XID_CONTINUE: https://www.unicode.org/reports/tr31/#Default_Identifier_Syntax
+// +, -, ., @, _: commonly used in file name including "." and ".."
+// /: path separator
+// \: path separator (Windows)
+// TODO: accept glob characters as identifier?
 identifier = @{
-  identifier_part ~ (("." | "-" | "+") ~ identifier_part)*
+  (XID_CONTINUE | "+" | "-" | "." | "@" | "_" | "/" | "\\")+
+}
+strict_identifier_part = @{ (ASCII_ALPHANUMERIC | "_")+ }
+strict_identifier = @{
+  strict_identifier_part ~ ("-" ~ strict_identifier_part)*
 }
 
 string_escape = @{ "\\" ~ ("t" | "r" | "n" | "0" | "\"" | "\\") }
@@ -42,7 +49,7 @@ function_arguments = {
 }
 
 // TODO: change rhs to string_literal to require quoting? #2101
-string_pattern = { identifier ~ pattern_kind_op ~ (identifier | string_literal) }
+string_pattern = { strict_identifier ~ pattern_kind_op ~ (identifier | string_literal) }
 
 primary = {
   "(" ~ whitespace* ~ expression ~ whitespace* ~ ")"
diff --git a/lib/src/fileset.rs b/lib/src/fileset.rs
index 1cbcab2f68..31368ae28d 100644
--- a/lib/src/fileset.rs
+++ b/lib/src/fileset.rs
@@ -396,8 +396,7 @@ mod tests {
             cwd: Path::new("/ws/cur"),
             workspace_root: Path::new("/ws"),
         };
-        // TODO: adjust identifier rule and test the expression parser instead
-        let parse = |input| FilePattern::parse(&ctx, input).map(FilesetExpression::pattern);
+        let parse = |text| parse(text, &ctx);
 
         // cwd-relative patterns
         assert_eq!(
diff --git a/lib/src/fileset_parser.rs b/lib/src/fileset_parser.rs
index 10a072cf05..ec41f4db80 100644
--- a/lib/src/fileset_parser.rs
+++ b/lib/src/fileset_parser.rs
@@ -40,8 +40,9 @@ impl Rule {
         match self {
             Rule::EOI => None,
             Rule::whitespace => None,
-            Rule::identifier_part => None,
             Rule::identifier => None,
+            Rule::strict_identifier_part => None,
+            Rule::strict_identifier => None,
             Rule::string_escape => None,
             Rule::string_content_char => None,
             Rule::string_content => None,
@@ -237,7 +238,7 @@ fn parse_primary_node(pair: Pair<Rule>) -> FilesetParseResult<ExpressionNode> {
         }
         Rule::string_pattern => {
             let (lhs, op, rhs) = first.into_inner().collect_tuple().unwrap();
-            assert_eq!(lhs.as_rule(), Rule::identifier);
+            assert_eq!(lhs.as_rule(), Rule::strict_identifier);
             assert_eq!(op.as_rule(), Rule::pattern_kind_op);
             let kind = lhs.as_str();
             let value = match rhs.as_rule() {
@@ -399,6 +400,18 @@ mod tests {
             parse_into_kind("dir/foo-bar_0.baz"),
             Ok(ExpressionKind::Identifier("dir/foo-bar_0.baz"))
         );
+        assert_eq!(
+            parse_into_kind("cli-reference@.md.snap"),
+            Ok(ExpressionKind::Identifier("cli-reference@.md.snap"))
+        );
+        assert_eq!(
+            parse_into_kind("柔術.jj"),
+            Ok(ExpressionKind::Identifier("柔術.jj"))
+        );
+        assert_eq!(
+            parse_into_kind(r#"Windows\Path"#),
+            Ok(ExpressionKind::Identifier(r#"Windows\Path"#))
+        );
     }
 
     #[test]