1 files changed, 4 insertions, 1 deletions
diff --git a/cli/js/compiler/sourcefile.ts b/cli/js/compiler/sourcefile.ts
index 159ccda85..e400acbf5 100644
--- a/cli/js/compiler/sourcefile.ts
+++ b/cli/js/compiler/sourcefile.ts
@@ -35,7 +35,10 @@ function getExtension(fileName: string, mediaType: MediaType): ts.Extension {
     case MediaType.TSX:
       return ts.Extension.Tsx;
     case MediaType.Json:
-      return ts.Extension.Json;
+      // we internally compile JSON, so what gets provided to the TypeScript
+      // compiler is an ES module, but in order to get TypeScript to handle it
+      // properly we have to pretend it is TS.
+      return ts.Extension.Ts;
     case MediaType.Wasm:
       // Custom marker for Wasm type.
       return ts.Extension.Js;