diff --git a/src/services/pullLanguageService.ts b/src/services/pullLanguageService.ts
index bd112a97fd..c8926cd4a5 100644
--- a/src/services/pullLanguageService.ts
+++ b/src/services/pullLanguageService.ts
@@ -480,8 +480,14 @@ module TypeScript.Services {
             var oldProgram = this.program;
             if (oldProgram) {
                 var oldSettings = this.program.getCompilerOptions();
+
+                // If the language version changed, then that affects what types of things we parse. So
+                // we have to dump all syntax trees.
+                // TODO: handle propagateEnumConstants
+                var settingsChangeAffectsSyntax = oldSettings.target !== compilationSettings.target;
+
                 var changesInCompilationSettingsAffectSyntax =
-                    oldSettings && compilationSettings && !compareDataObjects(oldSettings, compilationSettings) && settingsChangeAffectsSyntax(oldSettings, compilationSettings);
+                    oldSettings && compilationSettings && !compareDataObjects(oldSettings, compilationSettings) && settingsChangeAffectsSyntax;
                 var oldSourceFiles = this.program.getSourceFiles();
 
                 for (var i = 0, n = oldSourceFiles.length; i < n; i++) {
diff --git a/src/services/typescriptServices.ts b/src/services/typescriptServices.ts
index 21ae5f6a6f..4e27212687 100644
--- a/src/services/typescriptServices.ts
+++ b/src/services/typescriptServices.ts
@@ -46,7 +46,6 @@
 /// <reference path='compiler\referenceResolution.ts' />
 /// <reference path='compiler\precompile.ts' />
 /// <reference path='compiler\bloomFilter.ts' />
-/// <reference path='compiler\settings.ts' />
 /// <reference path='compiler\flags.ts' />
 /// <reference path='compiler\types.ts' />
 /// <reference path='compiler\ast.ts' />