diff --git a/src/lib_ffi.c b/src/lib_ffi.c
index 45065c12..361c3ba1 100644
--- a/src/lib_ffi.c
+++ b/src/lib_ffi.c
@@ -482,7 +482,7 @@ LJLIB_CF(ffi_fill)	LJLIB_REC(.)
 #define H_(le, be)	LJ_ENDIAN_SELECT(0x##le, 0x##be)
 
 /* Test ABI string. */
-LJLIB_CF(ffi_abi)
+LJLIB_CF(ffi_abi)	LJLIB_REC(.)
 {
   GCstr *s = lj_lib_checkstr(L, 1);
   int b = 0;
@@ -511,6 +511,7 @@ LJLIB_CF(ffi_abi)
     break;
   }
   setboolV(L->top-1, b);
+  setboolV(&G(L)->tmptv2, b);  /* Remember for trace recorder. */
   return 1;
 }
 
diff --git a/src/lj_crecord.c b/src/lj_crecord.c
index 8e68a5d6..73575fe2 100644
--- a/src/lj_crecord.c
+++ b/src/lj_crecord.c
@@ -1008,6 +1008,16 @@ void LJ_FASTCALL recff_ffi_fill(jit_State *J, RecordFFData *rd)
   }  /* else: interpreter will throw. */
 }
 
+void LJ_FASTCALL recff_ffi_abi(jit_State *J, RecordFFData *rd)
+{
+  if (tref_isstr(J->base[0])) {
+    /* Specialize to the ABI string to make the boolean result a constant. */
+    emitir(IRTG(IR_EQ, IRT_STR), J->base[0], lj_ir_kstr(J, strV(&rd->argv[0])));
+    J->postproc = LJ_POST_FIXBOOL;
+    J->base[0] = TREF_TRUE;
+  }  /* else: interpreter will throw. */
+}
+
 /* -- Miscellaneous library functions ------------------------------------- */
 
 void LJ_FASTCALL lj_crecord_tonumber(jit_State *J, RecordFFData *rd)
diff --git a/src/lj_crecord.h b/src/lj_crecord.h
index 1714f1c4..0199e0eb 100644
--- a/src/lj_crecord.h
+++ b/src/lj_crecord.h
@@ -19,6 +19,7 @@ LJ_FUNC void LJ_FASTCALL recff_ffi_new(jit_State *J, RecordFFData *rd);
 LJ_FUNC void LJ_FASTCALL recff_ffi_string(jit_State *J, RecordFFData *rd);
 LJ_FUNC void LJ_FASTCALL recff_ffi_copy(jit_State *J, RecordFFData *rd);
 LJ_FUNC void LJ_FASTCALL recff_ffi_fill(jit_State *J, RecordFFData *rd);
+LJ_FUNC void LJ_FASTCALL recff_ffi_abi(jit_State *J, RecordFFData *rd);
 LJ_FUNC void LJ_FASTCALL lj_crecord_tonumber(jit_State *J, RecordFFData *rd);
 #else
 #define recff_cdata_index	recff_nyi
@@ -29,6 +30,7 @@ LJ_FUNC void LJ_FASTCALL lj_crecord_tonumber(jit_State *J, RecordFFData *rd);
 #define recff_ffi_string	recff_nyi
 #define recff_ffi_copy		recff_nyi
 #define recff_ffi_fill		recff_nyi
+#define recff_ffi_abi		recff_nyi
 #endif
 
 #endif
diff --git a/src/lj_jit.h b/src/lj_jit.h
index 2f3df2a0..e2dd5fb8 100644
--- a/src/lj_jit.h
+++ b/src/lj_jit.h
@@ -112,7 +112,8 @@ typedef enum {
 typedef enum {
   LJ_POST_NONE,		/* No action. */
   LJ_POST_FIXCOMP,	/* Fixup comparison and emit pending guard. */
-  LJ_POST_FIXGUARD	/* Fixup and emit pending guard. */
+  LJ_POST_FIXGUARD,	/* Fixup and emit pending guard. */
+  LJ_POST_FIXBOOL	/* Fixup boolean result. */
 } PostProc;
 
 /* Machine code type. */
diff --git a/src/lj_record.c b/src/lj_record.c
index d8c67499..26e87ab3 100644
--- a/src/lj_record.c
+++ b/src/lj_record.c
@@ -1388,16 +1388,19 @@ void lj_record_ins(jit_State *J)
       rec_comp_fixup(J, pc, (!tvistruecond(&J2G(J)->tmptv2) ^ (bc_op(*pc)&1)));
       /* fallthrough */
     case LJ_POST_FIXGUARD:  /* Fixup and emit pending guard. */
+      if (!tvistruecond(&J2G(J)->tmptv2))
+	J->fold.ins.o ^= 1;  /* Flip guard to opposite. */
+      lj_opt_fold(J);  /* Emit pending guard. */
+      /* fallthrough */
+    case LJ_POST_FIXBOOL:
       if (!tvistruecond(&J2G(J)->tmptv2)) {
 	BCReg s;
-	J->fold.ins.o ^= 1;  /* Flip guard to opposite. */
 	for (s = 0; s < J->maxslot; s++)  /* Fixup stack slot (if any). */
 	  if (J->base[s] == TREF_TRUE && tvisfalse(&J->L->base[s])) {
 	    J->base[s] = TREF_FALSE;
 	    break;
 	  }
       }
-      lj_opt_fold(J);  /* Emit pending guard. */
       break;
     default: lua_assert(0); break;
     }