diff --git a/racket/src/racket/src/lightning/i386/core.h b/racket/src/racket/src/lightning/i386/core.h
index 512b54f3ed..7f9115edfd 100644
--- a/racket/src/racket/src/lightning/i386/core.h
+++ b/racket/src/racket/src/lightning/i386/core.h
@@ -473,9 +473,9 @@ struct jit_local_state {
 #define	jit_arg_p()	        (_jitl.nextarg_geti++)
 #define jit_arg_reg(p)          (jit_arg_reg_order[p])
 # ifdef _WIN64
-static const int const jit_arg_reg_order[] = { _ECX, _EDX, JIT_R(8), JIT_R(9) };
+static const int jit_arg_reg_order[] = { _ECX, _EDX, JIT_R(8), JIT_R(9) };
 # else
-static const int const jit_arg_reg_order[] = { _EDI, _ESI, _EDX, _ECX };
+static const int jit_arg_reg_order[] = { _EDI, _ESI, _EDX, _ECX };
 # endif
 #else
 #define	jit_arg_c()		((_jitl.framesize += sizeof(int)) - sizeof(int))
diff --git a/racket/src/racket/src/unwind/libunwind.c b/racket/src/racket/src/unwind/libunwind.c
index fcc1f850c7..9d59c216b5 100644
--- a/racket/src/racket/src/unwind/libunwind.c
+++ b/racket/src/racket/src/unwind/libunwind.c
@@ -1410,7 +1410,7 @@ put_unwind_info (struct dwarf_cursor *c, unw_proc_info_t *pi)
   if (!c->pi_valid)
     return;
 
-  if (pi->unwind_info);
+  if (pi->unwind_info)
     {
       /* free (pi->unwind_info); */
       pi->unwind_info = NULL;
diff --git a/racket/src/racket/src/unwind/libunwind_i.h b/racket/src/racket/src/unwind/libunwind_i.h
index 71c7b62451..84ad48a45c 100644
--- a/racket/src/racket/src/unwind/libunwind_i.h
+++ b/racket/src/racket/src/unwind/libunwind_i.h
@@ -92,6 +92,11 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 
 #define ARRAY_SIZE(a)	(sizeof (a) / sizeof ((a)[0]))
 
+#define UNWI_OBJ(fn)	  UNW_PASTE(UNW_PREFIX,UNW_PASTE(I,fn))
+#define UNWI_ARCH_OBJ(fn) UNW_PASTE(UNW_PASTE(UNW_PASTE(_UI,UNW_TARGET),_), fn)
+
+#ifndef UW_NO_SYNC
+
 /* Make it easy to write thread-safe code which may or may not be
    linked against libpthread.  The macros below can be used
    unconditionally and if -lpthread is around, they'll call the
@@ -152,9 +157,6 @@ cmpxchg_ptr (void *addr, void *old, void *new)
 #endif
 #define atomic_read(ptr)	(*(ptr))
 
-#define UNWI_OBJ(fn)	  UNW_PASTE(UNW_PREFIX,UNW_PASTE(I,fn))
-#define UNWI_ARCH_OBJ(fn) UNW_PASTE(UNW_PASTE(UNW_PASTE(_UI,UNW_TARGET),_), fn)
-
 #define unwi_full_mask    UNWI_ARCH_OBJ(full_mask)
 
 /* Type of a mask that can be used to inhibit preemption.  At the
@@ -179,6 +181,11 @@ do {						\
   sigprocmask (SIG_SETMASK, &(m), NULL);	\
 } while (0)
 
+#else  /* UW_NO_SYNC */
+# define atomic_read(ptr)	(*(ptr))
+typedef int intrmask_t;
+#endif /* UW_NO_SYNC */
+
 #define GET_MEMORY(mem, size_in_bytes)				    \
 do {									    \
   /* Hopefully, mmap() goes straight through to a system call stub...  */   \