diff --git a/build/dev.sh b/build/dev.sh
index aa0b999519..5f63d7e42e 100755
--- a/build/dev.sh
+++ b/build/dev.sh
@@ -135,8 +135,19 @@ oil-asdl-to-cpp() {
   # Instead of id__Eol_Tok, use Id::Eol_Tok.
   # case lex_mode_e::Expr
 
-  gen-asdl-cpp frontend/syntax.asdl
   gen-asdl-cpp osh/runtime.asdl
+
+  gen-asdl-cpp frontend/syntax.asdl
+
+  # CRAZY SHARP HACK to make Token 16 bytes instead of 24!  (And speck is 8
+  # bytes rather than 12, although we might want to get rid of it.)
+  # Because of C's weak type system (typedef int Id_t), this is better than
+  # changing ASDL.
+  local orig=_build/cpp/syntax_asdl.h 
+  local tmp=_devbuild/tmp/syntax_asdl.h
+  sed 's/Id_t id;/uint16_t id;/g' $orig > $tmp
+  diff -u $orig $tmp || true
+  mv -v $tmp $orig
 }
 
 oil-cpp() {