diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7ae46fa..993d465 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 - Fix issue [#328](https://github.com/intersystems/language-server/issues/328): Fix namespace detection for Diagnostic computation
 - Fix issue [#331](https://github.com/intersystems/language-server/issues/331): Fix display of method arguments with a colon in the default value
 - Fix issue [#333](https://github.com/intersystems/language-server/issues/333): Fix folding ranges when routine labels that don't appear in the first column
+- Fix issue [#335](https://github.com/intersystems/language-server/issues/335): Support U2 syntax when ROUTINE LanguageMode = 10
 - Parser changes:
   - DP-430950: Support new `Requires` Query keyword
 
diff --git a/server/src/parse/parse.ts b/server/src/parse/parse.ts
index 8251443..2761aaa 100644
--- a/server/src/parse/parse.ts
+++ b/server/src/parse/parse.ts
@@ -9,8 +9,9 @@ const acceptroutineheaderline = true;
 
 // flags to pass to Tokenize
 const IPARSE_UDL_EXPLICIT = 0x0001; // require variable declaration (#dim)
-const IPARSE_UDL_EXPERT = 0x4000; // this stops the SYSTEM class-keyword from being colored as a syntax-error
-const IPARSE_UDL_TRACK = 0x20000; // enable variable-tracking
+const IPARSE_UDL_EXPERT = 0x4000; // this stops the SYSTEM class keyword from being colored as a syntax error
+const IPARSE_COS_U2 = 0x10000; // accept U2 syntax
+const IPARSE_UDL_TRACK = 0x20000; // enable variable tracking
 // these flags are only passed for HTML documents
 const IPARSE_ALL_CSPEXTENSIONS = 0x0400; // all parsers: recognize CSP extensions like #(..)#
 const IPARSE_HTML_CSPMODE = 0x0800; // HTML parser: is in CSP mode
@@ -38,6 +39,11 @@ export function parseDocument(languageId: string, fileExt: string, text: string)
 		// color the routine header line
 		const routinelinecoloring: routineheadertype = colorRoutineLine(firstline);
 
+		if (routinelinecoloring?.routineheaderinfo?.languagemode == 10) {
+			// LanguageMode 10 is U2, so allow U2 syntax
+			flags += IPARSE_COS_U2;
+		}
+
 		// effectively replace the routine line (before the line-ending) with spaces so that the offsets are still correct
 		const doctoparse = ' '.repeat(firstline.length) + text.slice(firstline.length);
 
diff --git a/server/src/utils/types.ts b/server/src/utils/types.ts
index b7bd4b4..7d63eb5 100644
--- a/server/src/utils/types.ts
+++ b/server/src/utils/types.ts
@@ -167,10 +167,10 @@ export type compresseditem = {
 
 export type compressedline = compresseditem[];
 
-export type compressedresult = {'compressedlinearray': compressedline[], 'routineheaderinfo'?: routineheaderinfotype};
+export type compressedresult = { compressedlinearray: compressedline[], routineheaderinfo?: routineheaderinfotype };
 
-export type compressedcolors = {'compressedcolors': compressedline[]};
+export type compressedcolors = { compressedcolors: compressedline[] };
 
 
 // routine header (if present 'generated' is just set to '')
-export type routineheaderinfotype = {'routinename': string, 'routinetype'?: string, 'languagemode'?: number, 'generated'?: string};
+export type routineheaderinfotype = { routinename: string, routinetype?: string, languagemode?: number, generated?: string };