diff --git a/src/AnonymizedFile.ts b/src/AnonymizedFile.ts
index 3affcfa..d44d9d1 100644
--- a/src/AnonymizedFile.ts
+++ b/src/AnonymizedFile.ts
@@ -209,7 +209,7 @@ export default class AnonymizedFile {
     const mime = lookup(this.anonymizedPath);
     if (mime && this.extension() != "ts") {
       res.contentType(mime);
-    } else if (this.extension() != "ts") {
+    } else if (this.extension() == "ts") {
       res.contentType("application/x-typescript");
     } else if (isTextFile(this.anonymizedPath)) {
       res.contentType("text/plain");