diff --git a/src/mzscheme/include/schthread.h b/src/mzscheme/include/schthread.h
index daa47e1a72..c40910b45b 100644
--- a/src/mzscheme/include/schthread.h
+++ b/src/mzscheme/include/schthread.h
@@ -106,6 +106,8 @@ typedef struct Thread_Local_Variables {
   struct Scheme_Dynamic_Wind *available_prompt_dw_;
   struct Scheme_Meta_Continuation *available_prompt_mc_;
   struct Scheme_Object *cached_beg_stx_;
+  struct Scheme_Object *cached_mod_stx_;
+  struct Scheme_Object *cached_mod_beg_stx_;
   struct Scheme_Object *cached_dv_stx_;
   struct Scheme_Object *cached_ds_stx_;
   int cached_stx_phase_;
@@ -288,6 +290,8 @@ XFORM_GC_VARIABLE_STACK_THROUGH_THREAD_LOCAL;
 #define available_prompt_dw XOA (scheme_get_thread_local_variables()->available_prompt_dw_)
 #define available_prompt_mc XOA (scheme_get_thread_local_variables()->available_prompt_mc_)
 #define cached_beg_stx XOA (scheme_get_thread_local_variables()->cached_beg_stx_)
+#define cached_mod_stx XOA (scheme_get_thread_local_variables()->cached_mod_stx_)
+#define cached_mod_beg_stx XOA (scheme_get_thread_local_variables()->cached_mod_beg_stx_)
 #define cached_dv_stx XOA (scheme_get_thread_local_variables()->cached_dv_stx_)
 #define cached_ds_stx XOA (scheme_get_thread_local_variables()->cached_ds_stx_)
 #define cached_stx_phase XOA (scheme_get_thread_local_variables()->cached_stx_phase_)