diff --git a/src/configure b/src/configure
index 5dd4a89108..715a606311 100755
--- a/src/configure
+++ b/src/configure
@@ -6038,6 +6038,67 @@ fi
 
 if test "$inline" = "no" ; then
   MZOPTIONS="$MZOPTIONS -DNO_INLINE_KEYWORD"
+fi
+{ echo "$as_me:$LINENO: result: $inline" >&5
+echo "${ECHO_T}$inline" >&6; }
+
+ msg="for noinline attribute"
+{ echo "$as_me:$LINENO: checking $msg" >&5
+echo $ECHO_N "checking $msg... $ECHO_C" >&6; }
+if test "$cross_compiling" = yes; then
+  noinline=no
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+static int foo() __attribute__ ((noinline));
+   static int foo() { return 0; }
+   int main() {
+      return foo();
+   }
+_ACEOF
+rm -f conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
+  { (case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  noinline=yes
+else
+  echo "$as_me: program exited with status $ac_status" >&5
+echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+( exit $ac_status )
+noinline=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
+fi
+
+
+if test "$noinline" = "yes" ; then
+
+cat >>confdefs.h <<\_ACEOF
+#define MZ_USE_NOINLINE 1
+_ACEOF
+
 fi
 { echo "$as_me:$LINENO: result: $inline" >&5
 echo "${ECHO_T}$inline" >&6; }
diff --git a/src/mzscheme/configure.ac b/src/mzscheme/configure.ac
index e90eed7f25..55c680a812 100644
--- a/src/mzscheme/configure.ac
+++ b/src/mzscheme/configure.ac
@@ -722,12 +722,26 @@ AC_TRY_RUN(
    static inline int foo() { return 0; }
    int main() {
       return foo();
-   }, inline=yes, inline=no, inline=no)
+   }, 
+  inline=yes, inline=no, inline=no)
 if test "$inline" = "no" ; then
   MZOPTIONS="$MZOPTIONS -DNO_INLINE_KEYWORD"
 fi
 AC_MSG_RESULT($inline) 
 
+[ msg="for noinline attribute" ]
+AC_MSG_CHECKING($msg)
+AC_TRY_RUN(
+   static int foo() __attribute__ ((noinline));
+   static int foo() { return 0; }
+   int main() {
+      return foo();
+   }, noinline=yes, noinline=no, noinline=no)
+if test "$noinline" = "yes" ; then
+  AC_DEFINE(MZ_USE_NOINLINE,1,[Have noinline attribute])
+fi
+AC_MSG_RESULT($inline) 
+
 [ msg="for GNU preprocessor" ]
 AC_MSG_CHECKING($msg)
 AC_TRY_RUN(
diff --git a/src/mzscheme/mzconfig.h.in b/src/mzscheme/mzconfig.h.in
index 2d7056aacd..425fd7b2f3 100644
--- a/src/mzscheme/mzconfig.h.in
+++ b/src/mzscheme/mzconfig.h.in
@@ -32,5 +32,7 @@
 /* Whether getaddrinfo works. */
 #undef HAVE_GETADDRINFO
 
+/* Whether __attribute__ ((noinline)) works */
+#undef MZ_USE_NOINLINE
 
 #endif
diff --git a/src/mzscheme/src/fun.c b/src/mzscheme/src/fun.c
index 74810fb41d..d1f95d53bc 100644
--- a/src/mzscheme/src/fun.c
+++ b/src/mzscheme/src/fun.c
@@ -1827,7 +1827,8 @@ typedef Scheme_Object *(*Overflow_K_Proc)(void);
 THREAD_LOCAL Scheme_Overflow_Jmp *scheme_overflow_jmp;
 THREAD_LOCAL void *scheme_overflow_stack_start;
 
-/* private, but declared public to avoid inlining: */
+MZ_DO_NOT_INLINE(void scheme_really_create_overflow(void *stack_base));
+
 void scheme_really_create_overflow(void *stack_base)
 {
   Scheme_Overflow_Jmp *jmp;
@@ -5747,7 +5748,9 @@ void scheme_drop_prompt_meta_continuations(Scheme_Object *prompt_tag)
   scheme_current_thread->meta_continuation = mc;
 }
 
-/* private, but declared public to avoid inlining: */
+MZ_DO_NOT_INLINE(Scheme_Object *scheme_finish_apply_for_prompt(Scheme_Prompt *prompt, Scheme_Object *_prompt_tag, 
+                                                               Scheme_Object *proc, int argc, Scheme_Object **argv));
+
 Scheme_Object *scheme_finish_apply_for_prompt(Scheme_Prompt *prompt, Scheme_Object *_prompt_tag, 
                                               Scheme_Object *proc, int argc, Scheme_Object **argv)
 {
@@ -5887,7 +5890,9 @@ Scheme_Object *scheme_finish_apply_for_prompt(Scheme_Prompt *prompt, Scheme_Obje
   }
 }
 
-/* private, but declared public to avoid inlining: */
+MZ_DO_NOT_INLINE(Scheme_Object *scheme_apply_for_prompt(Scheme_Prompt *prompt, Scheme_Object *prompt_tag, 
+                                                        Scheme_Object *proc, int argc, Scheme_Object **argv));
+
 Scheme_Object *scheme_apply_for_prompt(Scheme_Prompt *prompt, Scheme_Object *prompt_tag, 
                                        Scheme_Object *proc, int argc, Scheme_Object **argv)
 {
diff --git a/src/mzscheme/src/schpriv.h b/src/mzscheme/src/schpriv.h
index 7c9b7cc040..a37bd4b790 100644
--- a/src/mzscheme/src/schpriv.h
+++ b/src/mzscheme/src/schpriv.h
@@ -104,6 +104,13 @@ int scheme_num_types(void);
 # define SET_REQUIRED_TAG(e) /* empty */
 #endif
 
+#if MZ_USE_NOINLINE
+# define MZ_DO_NOT_INLINE(decl) decl __attribute__ ((noinline));
+#else
+# define MZ_DO_NOT_INLINE()
+#endif
+
+
 void scheme_reset_finalizations(void);
 
 extern unsigned long scheme_get_current_os_thread_stack_base(void);
diff --git a/src/mzscheme/src/setjmpup.c b/src/mzscheme/src/setjmpup.c
index 8aad99bf14..57e3dca67b 100644
--- a/src/mzscheme/src/setjmpup.c
+++ b/src/mzscheme/src/setjmpup.c
@@ -325,7 +325,9 @@ void MZ_NO_INLINE scheme_copy_stack(Scheme_Jumpup_Buf *b, void *base, void *star
 	 size);
 }
 
-static void uncopy_stack(int ok, Scheme_Jumpup_Buf *b, long *prev)
+MZ_DO_NOT_INLINE(void scheme_uncopy_stack(int ok, Scheme_Jumpup_Buf *b, long *prev));
+
+void scheme_uncopy_stack(int ok, Scheme_Jumpup_Buf *b, long *prev)
 {
   GC_CAN_IGNORE Scheme_Jumpup_Buf *c;
   long top_delta = 0, bottom_delta = 0, size;
@@ -337,7 +339,7 @@ static void uncopy_stack(int ok, Scheme_Jumpup_Buf *b, long *prev)
 
     z = (unsigned long)&junk[0];
 
-    uncopy_stack(STK_COMP(z, DEEPPOS(b)), b, junk);
+    scheme_uncopy_stack(STK_COMP(z, DEEPPOS(b)), b, junk);
   }
 
   /* Vague attempt to prevent the compiler from optimizing away `prev': */
@@ -619,7 +621,7 @@ void scheme_longjmpup(Scheme_Jumpup_Buf *b)
   scheme_flush_stack_cache();
 #endif
 
-  uncopy_stack(STK_COMP((unsigned long)&z, DEEPPOS(b)), b, junk);
+  scheme_uncopy_stack(STK_COMP((unsigned long)&z, DEEPPOS(b)), b, junk);
 }
 
 void scheme_init_jmpup_buf(Scheme_Jumpup_Buf *b)
diff --git a/src/mzscheme/src/thread.c b/src/mzscheme/src/thread.c
index dde50e7cf7..4fff4b5ee6 100644
--- a/src/mzscheme/src/thread.c
+++ b/src/mzscheme/src/thread.c
@@ -3222,7 +3222,8 @@ static Scheme_Object *def_nested_exn_handler(int argc, Scheme_Object *argv[])
   return scheme_void; /* misuse of exception handler (wrong kind of thread or under prompt) */
 }
 
-/* private, but declared as public to avoid inlining: */
+MZ_DO_NOT_INLINE(Scheme_Object *scheme_call_as_nested_thread(int argc, Scheme_Object *argv[], void *max_bottom));
+
 Scheme_Object *scheme_call_as_nested_thread(int argc, Scheme_Object *argv[], void *max_bottom)
 {
   Scheme_Thread *p = scheme_current_thread;
@@ -3791,7 +3792,7 @@ static void raise_break(Scheme_Thread *p)
 
   p->external_break = 0;
 
-  if (p->blocker && (p->block_check == syncing_ready)) {
+  if (p->blocker && (p->block_check == (Scheme_Ready_Fun)syncing_ready)) {
     /* Get out of lines for channels, etc., before calling a break exn handler. */
     scheme_post_syncing_nacks((Syncing *)p->blocker);
   }