diff --git a/racket/src/racket/src/jit.h b/racket/src/racket/src/jit.h
index 57e9e81ee8..aac5241a6b 100644
--- a/racket/src/racket/src/jit.h
+++ b/racket/src/racket/src/jit.h
@@ -83,6 +83,11 @@ END_XFORM_ARITH;
 # define _jit_epilog scheme_jit_epilog
 #endif
 
+/* The ABI for _CALL_DARWIN or JIT_X86_64 requires alignment. Even
+   when it's not required, it's better for performance when flonums
+   are stored on the stack. */
+#define JIT_X86_ALIGN_STACK 1
+
 #ifndef DEFINE_LIGHTNING_FUNCS
 # define SUPPRESS_LIGHTNING_FUNCS
 #endif
@@ -936,11 +941,7 @@ void scheme_jit_prolog_again(mz_jit_state *jitter, int n, int ret_addr_reg)
 # define mz_get_local_p_x(x, l, FP) jit_ldxi_p((x), FP, (l))
 # define mz_patch_branch_at(a, v) jit_patch_branch_at(a, v)
 # define mz_patch_ucbranch_at(a, v) jit_patch_ucbranch_at(a, v)
-  /* The ABI for _CALL_DARWIN or JIT_X86_64 requires alignment. Even
-     when it's not required, it's better for performance when flonums
-     are stored on the stack. */
-# define X86_ALIGN_STACK 1
-# ifdef X86_ALIGN_STACK
+# ifdef JIT_X86_ALIGN_STACK
    /* Maintain 16-byte stack alignment. */
 #  ifdef JIT_X86_64
 #   define STACK_ALIGN_WORDS 1
diff --git a/racket/src/racket/src/jitcommon.c b/racket/src/racket/src/jitcommon.c
index b6ca4fe184..bb6625d836 100644
--- a/racket/src/racket/src/jitcommon.c
+++ b/racket/src/racket/src/jitcommon.c
@@ -82,7 +82,7 @@ static int save_struct_temp(mz_jit_state *jitter, int reg)
   jit_movr_p(JIT_V(3), reg);
 #endif
 #ifdef MZ_USE_JIT_I386
-# ifdef X86_ALIGN_STACK
+# ifdef JIT_X86_ALIGN_STACK
   mz_set_local_p(reg, JIT_LOCAL3);
 # else
   jit_pushr_p(reg);
@@ -101,7 +101,7 @@ static int restore_struct_temp(mz_jit_state *jitter, int reg)
   jit_movr_p(reg, JIT_V(3));
 #endif
 #ifdef MZ_USE_JIT_I386
-# ifdef X86_ALIGN_STACK
+# ifdef JIT_X86_ALIGN_STACK
   mz_get_local_p(reg, JIT_LOCAL3);
 # else
   jit_popr_p(reg);
@@ -1714,7 +1714,7 @@ int scheme_generate_struct_op(mz_jit_state *jitter, int kind, int for_branch,
     } else {
       mz_patch_ucbranch(bref_true);
 #ifdef MZ_USE_JIT_I386
-# ifndef X86_ALIGN_STACK
+# ifndef JIT_X86_ALIGN_STACK
       jit_popr_p(JIT_V1);
 # endif
 #endif
diff --git a/racket/src/racket/src/lightning/i386/core.h b/racket/src/racket/src/lightning/i386/core.h
index 46e392dadc..133933a7db 100644
--- a/racket/src/racket/src/lightning/i386/core.h
+++ b/racket/src/racket/src/lightning/i386/core.h
@@ -417,7 +417,7 @@ struct jit_local_state {
 /* Stack isn't used for arguments: */
 # define jit_prepare_i(ni)	(_jitl.argssize = (ni), _jitl.argpushes = _jitl.argssize)
 #else
-# ifdef _CALL_DARWIN
+# if defined(_CALL_DARWIN) || defined(JIT_X86_ALIGN_STACK)
   /* Stack must stay 16-byte aligned: */
 #  define jit_prepare_i(ni)	(((ni & 0x3) \
                                   ? SUBLir(4 * ((((ni) + 3) & ~(0x3)) - (ni)), JIT_SP) \