diff --git a/lisp-kernel/thread_manager.c b/lisp-kernel/thread_manager.c
index 7703ae49..93ce3832 100644
--- a/lisp-kernel/thread_manager.c
+++ b/lisp-kernel/thread_manager.c
@@ -1368,9 +1368,11 @@ shutdown_thread_tcr(void *arg)
     if (tcr->flags & (1<<TCR_FLAG_BIT_FOREIGN)) {
       LispObj callback_macptr = nrs_FOREIGN_THREAD_CONTROL.vcell,
 	callback_ptr = ((macptr *)ptr_from_lispobj(untag(callback_macptr)))->address;
-    
+      int (*foreign_thread_control)(int) = (int (*)(int))callback_ptr;
+
       tsd_set(lisp_global(TCR_KEY), TCR_TO_TSD(tcr));
-      ((void (*)())ptr_from_lispobj(callback_ptr))(1);
+      foreign_thread_control(1);
+      //((void (*)(int))ptr_from_lispobj(callback_ptr))(1);
       tsd_set(lisp_global(TCR_KEY), NULL);
     }
 #ifdef DARWIN
@@ -1847,6 +1849,7 @@ get_tcr(Boolean create)
   if ((current == NULL) && create) {
     LispObj callback_macptr = nrs_FOREIGN_THREAD_CONTROL.vcell,
       callback_ptr = ((macptr *)ptr_from_lispobj(untag(callback_macptr)))->address;
+    int (*foreign_thread_control)(int) = (int (*)(int))callback_ptr;
     int i, nbindwords = 0;
     extern natural initial_stack_size;
     
@@ -1877,13 +1880,13 @@ get_tcr(Boolean create)
       *(--current->save_vsp) = 0;
       current->vs_area->active -= node_size;
     }
-    nbindwords = ((int (*)())ptr_from_lispobj(callback_ptr))(-1);
+    nbindwords = foreign_thread_control(-1);
     for (i = 0; i < nbindwords; i++) {
       *(--current->save_vsp) = 0;
       current->vs_area->active -= node_size;
     }
     TCR_AUX(current)->shutdown_count = 1;
-    ((void (*)())ptr_from_lispobj(callback_ptr))(0);
+    foreign_thread_control(0);
 
   }
   
@@ -2047,7 +2050,7 @@ create_thread_context_frame(mach_port_t, natural *, siginfo_t *, TCR*, native_th
 
 Boolean mach_suspend_tcr(TCR *tcr)
 {
-  thread_act_t thread = (thread_act_t)(tcr->native_thread_id);
+  mach_port_t thread = (mach_port_t)((intptr_t)tcr->native_thread_id);
   kern_return_t kret = thread_suspend(thread);
 
   if (kret == 0) {
@@ -2209,7 +2212,7 @@ resume_tcr(TCR *tcr)
 Boolean mach_resume_tcr(TCR *tcr)
 {
   ExceptionInformation *xp = tcr->suspend_context;
-  mach_port_t thread = (mach_port_t)(tcr->native_thread_id);
+  mach_port_t thread = (mach_port_t)((intptr_t)(tcr->native_thread_id));
 #if WORD_SIZE == 64
   MCONTEXT_T mc = UC_MCONTEXT(xp);
 #else
diff --git a/lisp-kernel/x86-exceptions.c b/lisp-kernel/x86-exceptions.c
index 75dea85e..6eeee55a 100644
--- a/lisp-kernel/x86-exceptions.c
+++ b/lisp-kernel/x86-exceptions.c
@@ -678,7 +678,6 @@ handle_alloc_trap(ExceptionInformation *xp, TCR *tcr, Boolean *notify)
   return true;
 }
 
-  
 int
 callback_to_lisp (TCR * tcr, LispObj callback_macptr, ExceptionInformation *xp,
                   natural arg1, natural arg2, natural arg3, natural arg4, natural arg5)
@@ -712,8 +711,12 @@ callback_to_lisp (TCR * tcr, LispObj callback_macptr, ExceptionInformation *xp,
      pointers (and at least should have called prepare_for_callback()).
   */
   callback_ptr = ((macptr *)ptr_from_lispobj(untag(callback_macptr)))->address;
+  typedef int (*callback_fn_type)(ExceptionInformation *, natural, natural,
+                                  natural, natural, natural);
+  callback_fn_type callback_fn = (callback_fn_type)callback_ptr;
+
   UNLOCK(lisp_global(EXCEPTION_LOCK), tcr);
-  delta = ((int (*)())callback_ptr) (xp, arg1, arg2, arg3, arg4, arg5);
+  delta = callback_fn(xp, arg1, arg2, arg3, arg4, arg5);
   LOCK(lisp_global(EXCEPTION_LOCK), tcr);
 
 #ifdef X8632