diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 28e9b114ec3..76800d77b3c 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -1207,6 +1207,7 @@ module ts {
         }
     }
 
+    // @internal
     export function createDiagnosticCollection(): DiagnosticCollection {
         var nonFileDiagnostics: Diagnostic[] = [];
         var fileDiagnostics: Map<Diagnostic[]> = {};
@@ -1336,4 +1337,4 @@ module ts {
             s.replace(nonAsciiCharacters, c => get16BitUnicodeEscapeSequence(c.charCodeAt(0))) :
             s;
     }
-}
\ No newline at end of file
+}