diff --git a/src/vm_x64.dasc b/src/vm_x64.dasc
index 9e0f58fd..16af1f29 100644
--- a/src/vm_x64.dasc
+++ b/src/vm_x64.dasc
@@ -1411,17 +1411,15 @@ static void build_subroutines(BuildCtx *ctx)
   |  checkint RA, ->fff_fallback
   |.else
   |  checknumtp [BASE+8], ->fff_fallback
-  |  movsd xmm0, qword [BASE+8]
+  |  cvttsd2si RAd, qword [BASE+8]
   |.endif
   |  mov PC, [BASE-8]
-  |.if DUALNUM
   |  add RAd, 1
+  |.if DUALNUM
   |  setint ITYPE, RA
   |  mov [BASE-16], ITYPE
   |.else
-  |  sseconst_1 xmm1, TMPR
-  |  addsd xmm0, xmm1
-  |  cvttsd2si RAd, xmm0
+  |  cvtsi2sd xmm0, RAd
   |  movsd qword [BASE-16], xmm0
   |.endif
   |  cmp RAd, TAB:RB->asize;  jae >2	// Not in array part?
diff --git a/src/vm_x86.dasc b/src/vm_x86.dasc
index 7e3d68a0..2c938656 100644
--- a/src/vm_x86.dasc
+++ b/src/vm_x86.dasc
@@ -1730,10 +1730,9 @@ static void build_subroutines(BuildCtx *ctx)
   |  mov dword [BASE-4], LJ_TISNUM
   |  mov dword [BASE-8], RD
   |.else
-  |  movsd xmm0, qword [BASE+8]
-  |  sseconst_1 xmm1, RBa
-  |  addsd xmm0, xmm1
-  |  cvttsd2si RD, xmm0
+  |  cvttsd2si RD, qword [BASE+8]
+  |  add RD, 1
+  |  cvtsi2sd xmm0, RD
   |  movsd qword [BASE-8], xmm0
   |.endif
   |  mov TAB:RB, [BASE]