diff --git a/py/persistentcode.c b/py/persistentcode.c
index f3d6b7205d..0b5da80774 100644
--- a/py/persistentcode.c
+++ b/py/persistentcode.c
@@ -617,7 +617,6 @@ void mp_raw_code_save(mp_compiled_module_t *cm, mp_print_t *print) {
     //  byte  version
     //  byte  feature flags
     //  byte  number of bits in a small int
-    //  uint  size of qstr window
     byte header[4] = {
         'M',
         MPY_VERSION,