diff --git a/src/mzscheme/src/future.c b/src/mzscheme/src/future.c
index cf6ae59297..b10d589a2c 100644
--- a/src/mzscheme/src/future.c
+++ b/src/mzscheme/src/future.c
@@ -1003,6 +1003,12 @@ static void receive_special_result(future_t *f, Scheme_Object *retval)
     p->ku.multiple.array = f->multiple_array;
     p->ku.multiple.count = f->multiple_count;
     f->multiple_array = NULL;
+  } else if (SAME_OBJ(retval, SCHEME_TAIL_CALL_WAITING)) {
+    Scheme_Thread *p = scheme_current_thread;
+
+    p->ku.apply.tail_rator = f->tail_rator;
+    p->ku.apply.tail_rands = f->tail_rands;
+    p->ku.apply.tail_num_rands = f->num_tail_rands;
   }
 }
 
@@ -1017,6 +1023,14 @@ static void send_special_result(future_t *f, Scheme_Object *retval)
     f->multiple_count = p->ku.multiple.count;
     if (SAME_OBJ(p->ku.multiple.array, p->values_buffer))
       p->values_buffer = NULL;
+  } else if (SAME_OBJ(retval, SCHEME_TAIL_CALL_WAITING)) {
+    Scheme_Thread *p = scheme_current_thread;
+
+    f->tail_rator = p->ku.apply.tail_rator;
+    f->tail_rands = p->ku.apply.tail_rands;
+    f->num_tail_rands = p->ku.apply.tail_num_rands;
+    p->ku.apply.tail_rator = NULL;
+    p->ku.apply.tail_rands = NULL;
   }
 }
 
diff --git a/src/mzscheme/src/future.h b/src/mzscheme/src/future.h
index 6b5007ff0b..2db66dfc7a 100644
--- a/src/mzscheme/src/future.h
+++ b/src/mzscheme/src/future.h
@@ -90,6 +90,10 @@ typedef struct future_t {
   Scheme_Object **multiple_array;
   int multiple_count;
 
+  Scheme_Object *tail_rator;
+  Scheme_Object **tail_rands;
+  int num_tail_rands;
+
   Scheme_Object *retval;
   struct future_t *prev;
   struct future_t *next;
diff --git a/src/mzscheme/src/gen-jit-ts.ss b/src/mzscheme/src/gen-jit-ts.ss
index 428c41881c..e7413ce057 100644
--- a/src/mzscheme/src/gen-jit-ts.ss
+++ b/src/mzscheme/src/gen-jit-ts.ss
@@ -43,6 +43,7 @@
      static @|result-type| ts_ ## id(@|args|) \
      { \
        START_XFORM_SKIP; \
+       LOG_PRIM_START(&id); \
        if (scheme_use_rtcall) \
          @|return| scheme_rtcall_@|t|(id, @(string-join arg-names ", ")); \
        else \
diff --git a/src/mzscheme/src/jit.c b/src/mzscheme/src/jit.c
index e75936874b..413b4e8db7 100644
--- a/src/mzscheme/src/jit.c
+++ b/src/mzscheme/src/jit.c
@@ -380,6 +380,12 @@ static void *decrement_cache_stack_pos(void *p)
 THREAD_LOCAL_DECL(static Scheme_Object **fixup_runstack_base);
 THREAD_LOCAL_DECL(static int fixup_already_in_place);
 
+/* FIXME?: If _scheme_tail_apply_from_native_fixup_args is called from
+   a future thread, then the wrong thread-local `fixup_runstack_base'
+   was set. But exercising this code seems to be impossible, maybe
+   because current bytecode optimizations never produce the case that
+   _scheme_tail_apply_from_native_fixup_args() was design to support. */
+
 static Scheme_Object *_scheme_tail_apply_from_native_fixup_args(Scheme_Object *rator,
                                                                 int argc,
                                                                 Scheme_Object **argv)
@@ -3274,7 +3280,7 @@ static int generate_app(Scheme_App_Rec *app, Scheme_Object **alt_rands, int num_
           && !(SCHEME_LOCAL_FLAGS(v) & SCHEME_LOCAL_OTHER_CLEARS)) {
         int pos;
         pos = mz_remap(SCHEME_LOCAL_POS(v));
-        if (pos == (jitter->depth + args_already_in_place))
+        if (pos == (jitter->depth + jitter->extra_pushed + args_already_in_place))
           args_already_in_place++;
         else
           break;
diff --git a/src/mzscheme/src/jit_ts_def.c b/src/mzscheme/src/jit_ts_def.c
index 2d98325f88..838dadf60d 100644
--- a/src/mzscheme/src/jit_ts_def.c
+++ b/src/mzscheme/src/jit_ts_def.c
@@ -2,6 +2,7 @@
 static Scheme_Object* ts_ ## id(Scheme_Object* g7, int g8, Scheme_Object** g9) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_siS_s(id, g7, g8, g9); \
   else \
@@ -12,6 +13,7 @@ static Scheme_Object* ts_ ## id(Scheme_Object* g7, int g8, Scheme_Object** g9) \
 static Scheme_Object* ts_ ## id(int g10, Scheme_Object** g11, Scheme_Object* g12) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_iSs_s(id, g10, g11, g12); \
   else \
@@ -22,6 +24,7 @@ static Scheme_Object* ts_ ## id(int g10, Scheme_Object** g11, Scheme_Object* g12
 static Scheme_Object* ts_ ## id(Scheme_Object* g13) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_s_s(id, g13); \
   else \
@@ -32,6 +35,7 @@ static Scheme_Object* ts_ ## id(Scheme_Object* g13) \
 static Scheme_Object* ts_ ## id(Scheme_Native_Closure_Data* g14) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_n_s(id, g14); \
   else \
@@ -42,6 +46,7 @@ static Scheme_Object* ts_ ## id(Scheme_Native_Closure_Data* g14) \
 static Scheme_Object* ts_ ## id() \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall__s(id, ); \
   else \
@@ -52,6 +57,7 @@ static Scheme_Object* ts_ ## id() \
 static Scheme_Object* ts_ ## id(Scheme_Object* g15, Scheme_Object* g16) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_ss_s(id, g15, g16); \
   else \
@@ -62,6 +68,7 @@ static Scheme_Object* ts_ ## id(Scheme_Object* g15, Scheme_Object* g16) \
 static MZ_MARK_STACK_TYPE ts_ ## id(Scheme_Object* g17, Scheme_Object* g18) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_ss_m(id, g17, g18); \
   else \
@@ -72,6 +79,7 @@ static MZ_MARK_STACK_TYPE ts_ ## id(Scheme_Object* g17, Scheme_Object* g18) \
 static Scheme_Object* ts_ ## id(Scheme_Object** g19, long g20) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_Sl_s(id, g19, g20); \
   else \
@@ -82,6 +90,7 @@ static Scheme_Object* ts_ ## id(Scheme_Object** g19, long g20) \
 static Scheme_Object* ts_ ## id(long g21) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_l_s(id, g21); \
   else \
@@ -92,6 +101,7 @@ static Scheme_Object* ts_ ## id(long g21) \
 static void ts_ ## id(Scheme_Bucket* g22, Scheme_Object* g23, int g24) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
      scheme_rtcall_bsi_v(id, g22, g23, g24); \
   else \
@@ -102,6 +112,7 @@ static void ts_ ## id(Scheme_Bucket* g22, Scheme_Object* g23, int g24) \
 static void ts_ ## id(int g25, int g26, Scheme_Object** g27) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
      scheme_rtcall_iiS_v(id, g25, g26, g27); \
   else \
@@ -112,6 +123,7 @@ static void ts_ ## id(int g25, int g26, Scheme_Object** g27) \
 static void ts_ ## id(Scheme_Object* g28, Scheme_Object* g29) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
      scheme_rtcall_ss_v(id, g28, g29); \
   else \
@@ -122,6 +134,7 @@ static void ts_ ## id(Scheme_Object* g28, Scheme_Object* g29) \
 static void ts_ ## id(Scheme_Bucket* g30) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
      scheme_rtcall_b_v(id, g30); \
   else \
@@ -132,6 +145,7 @@ static void ts_ ## id(Scheme_Bucket* g30) \
 static Scheme_Object* ts_ ## id(Scheme_Object* g31, long g32) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_sl_s(id, g31, g32); \
   else \
@@ -142,6 +156,7 @@ static Scheme_Object* ts_ ## id(Scheme_Object* g31, long g32) \
 static Scheme_Object* ts_ ## id(int g33, Scheme_Object** g34) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_iS_s(id, g33, g34); \
   else \
@@ -152,6 +167,7 @@ static Scheme_Object* ts_ ## id(int g33, Scheme_Object** g34) \
 static Scheme_Object* ts_ ## id(Scheme_Object** g35) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_S_s(id, g35); \
   else \
@@ -162,6 +178,7 @@ static Scheme_Object* ts_ ## id(Scheme_Object** g35) \
 static void ts_ ## id(Scheme_Object* g36) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
      scheme_rtcall_s_v(id, g36); \
   else \
@@ -172,6 +189,7 @@ static void ts_ ## id(Scheme_Object* g36) \
 static Scheme_Object* ts_ ## id(int g37, Scheme_Object** g38, int g39) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_iSi_s(id, g37, g38, g39); \
   else \
@@ -182,6 +200,7 @@ static Scheme_Object* ts_ ## id(int g37, Scheme_Object** g38, int g39) \
 static void ts_ ## id(Scheme_Object* g40, int g41, Scheme_Object** g42) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
      scheme_rtcall_siS_v(id, g40, g41, g42); \
   else \
@@ -192,6 +211,7 @@ static void ts_ ## id(Scheme_Object* g40, int g41, Scheme_Object** g42) \
 static void* ts_ ## id(size_t g43) \
 { \
   START_XFORM_SKIP; \
+  LOG_PRIM_START(&id); \
   if (scheme_use_rtcall) \
     return scheme_rtcall_z_p(id, g43); \
   else \
diff --git a/src/mzscheme/src/mzmark.c b/src/mzscheme/src/mzmark.c
index 39d52678fe..db5cbca0e4 100644
--- a/src/mzscheme/src/mzmark.c
+++ b/src/mzscheme/src/mzmark.c
@@ -5434,6 +5434,8 @@ static int future_MARK(void *p) {
   gcMARK(f->retval_s);
   gcMARK(f->retval);
   gcMARK(f->multiple_array);
+  gcMARK(f->tail_rator);
+  gcMARK(f->tail_rands);
   gcMARK(f->prev);
   gcMARK(f->next);
   gcMARK(f->next_waiting_atomic);
@@ -5457,6 +5459,8 @@ static int future_FIXUP(void *p) {
   gcFIXUP(f->retval_s);
   gcFIXUP(f->retval);
   gcFIXUP(f->multiple_array);
+  gcFIXUP(f->tail_rator);
+  gcFIXUP(f->tail_rands);
   gcFIXUP(f->prev);
   gcFIXUP(f->next);
   gcFIXUP(f->next_waiting_atomic);
diff --git a/src/mzscheme/src/mzmarksrc.c b/src/mzscheme/src/mzmarksrc.c
index b772e4f527..47c96e960c 100644
--- a/src/mzscheme/src/mzmarksrc.c
+++ b/src/mzscheme/src/mzmarksrc.c
@@ -2237,6 +2237,8 @@ future {
   gcMARK(f->retval_s);
   gcMARK(f->retval);
   gcMARK(f->multiple_array);
+  gcMARK(f->tail_rator);
+  gcMARK(f->tail_rands);
   gcMARK(f->prev);
   gcMARK(f->next);
   gcMARK(f->next_waiting_atomic);