diff --git a/src/services/services.ts b/src/services/services.ts
index e089f6e1764..dde5df7cd73 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -4942,8 +4942,7 @@ namespace ts {
         function getDocumentHighlights(fileName: string, position: number, filesToSearch: string[]): DocumentHighlights[] {
             synchronizeHostData();
 
-            filesToSearch = map(filesToSearch, normalizeSlashes);
-            const sourceFilesToSearch = filter(program.getSourceFiles(), f => contains(filesToSearch, f.fileName));
+            const sourceFilesToSearch = map(filesToSearch, f => program.getSourceFile(f));
             const sourceFile = getValidSourceFile(fileName);
 
             const node = getTouchingWord(sourceFile, position);