1 files changed, 16 insertions, 2 deletions
diff --git a/runtime/js/90_deno_ns.js b/runtime/js/90_deno_ns.js
index bba1f30d7..a957ce004 100644
--- a/runtime/js/90_deno_ns.js
+++ b/runtime/js/90_deno_ns.js
@@ -92,8 +92,22 @@ const denoNs = {
   lstat: fs.lstat,
   truncateSync: fs.truncateSync,
   truncate: fs.truncate,
-  ftruncateSync: fs.ftruncateSync,
-  ftruncate: fs.ftruncate,
+  ftruncateSync(rid, len) {
+    internals.warnOnDeprecatedApi(
+      "Deno.ftruncateSync()",
+      new Error().stack,
+      "Use `Deno.FsFile.truncateSync()` instead.",
+    );
+    return fs.ftruncateSync(rid, len);
+  },
+  ftruncate(rid, len) {
+    internals.warnOnDeprecatedApi(
+      "Deno.ftruncate()",
+      new Error().stack,
+      "Use `Deno.FsFile.truncate()` instead.",
+    );
+    return fs.ftruncate(rid, len);
+  },
   futime: fs.futime,
   futimeSync: fs.futimeSync,
   errors: errors.errors,