diff --git a/shift0.S b/shift0.S
index 44fe585..f624ec9 100644
--- a/shift0.S
+++ b/shift0.S
@@ -41,6 +41,7 @@ reset_arg:
     .cfi_offset 7, -20
 # allocate the new stack
     pushl   $STACKSIZE
+# it would be nice if caller could specify a desired stack size
     call    malloc
     addl    $4, %esp
 # push the stack on the stack of stacks
diff --git a/shift0ops.c b/shift0ops.c
index 7364a19..a521c0f 100644
--- a/shift0ops.c
+++ b/shift0ops.c
@@ -62,7 +62,7 @@ void *_shift_arg_internal(struct cont *c, struct shift_str *s)
 
 void *shift_arg(shiftable_arg_t f, void *arg)
 {
-    struct shift_str s;
+    struct shift_str s;  /* this looks like it could get overridden after return */
     s.f = f;
     s.arg = arg;
     return shift0_arg((shiftable_arg_t) _shift_arg_internal, (void*) &s);