diff --git a/js/moz.configure b/js/moz.configure
index d47c22fdf67fd..cbcaf38f01c9d 100644
--- a/js/moz.configure
+++ b/js/moz.configure
@@ -759,20 +759,14 @@ set_define("ENABLE_WASM_GC", wasm_gc)
 # ==========================================
 
 
-@depends(milestone.is_nightly)
-def default_wasm_js_string_builtins(is_nightly):
-    if is_nightly:
-        return True
-
-
 option(
-    "--enable-wasm-js-string-builtins",
-    default=default_wasm_js_string_builtins,
+    "--disable-wasm-js-string-builtins",
+    default=True,
     help="{Enable|Disable} WebAssembly JS String Builtins",
 )
 
 
-@depends("--enable-wasm-js-string-builtins", "--wasm-no-experimental")
+@depends("--disable-wasm-js-string-builtins", "--wasm-no-experimental")
 def wasm_js_string_builtins(value, no_experimental):
     if no_experimental or not value:
         return