diff --git a/src/lj_asm.c b/src/lj_asm.c
index a1e92003..7542c77c 100644
--- a/src/lj_asm.c
+++ b/src/lj_asm.c
@@ -1198,7 +1198,7 @@ static void asm_collectargs(ASMState *as, IRIns *ir,
 			    const CCallInfo *ci, IRRef *args)
 {
   uint32_t n = CCI_XNARGS(ci);
-  lua_assert(n <= CCI_NARGS_MAX);
+  lua_assert(n <= CCI_NARGS_MAX*2);  /* Account for split args. */
   if ((ci->flags & CCI_L)) { *args++ = ASMREF_L; n--; }
   while (n-- > 1) {
     ir = IR(ir->op1);
diff --git a/src/lj_asm_arm.h b/src/lj_asm_arm.h
index 1e024dcd..ddf1480f 100644
--- a/src/lj_asm_arm.h
+++ b/src/lj_asm_arm.h
@@ -455,7 +455,7 @@ static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
 
 static void asm_callx(ASMState *as, IRIns *ir)
 {
-  IRRef args[CCI_NARGS_MAX];
+  IRRef args[CCI_NARGS_MAX*2];
   CCallInfo ci;
   IRRef func;
   IRIns *irf;
@@ -2132,7 +2132,7 @@ static void asm_tail_prep(ASMState *as)
 /* Ensure there are enough stack slots for call arguments. */
 static Reg asm_setup_call_slots(ASMState *as, IRIns *ir, const CCallInfo *ci)
 {
-  IRRef args[CCI_NARGS_MAX];
+  IRRef args[CCI_NARGS_MAX*2];
   uint32_t i, nargs = CCI_XNARGS(ci);
   int nslots = 0, ngpr = REGARG_NUMGPR, nfpr = REGARG_NUMFPR, fprodd = 0;
   asm_collectargs(as, ir, ci, args);
diff --git a/src/lj_asm_mips.h b/src/lj_asm_mips.h
index 5070a7a2..fe7d55d3 100644
--- a/src/lj_asm_mips.h
+++ b/src/lj_asm_mips.h
@@ -328,7 +328,7 @@ static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
 
 static void asm_callx(ASMState *as, IRIns *ir)
 {
-  IRRef args[CCI_NARGS_MAX];
+  IRRef args[CCI_NARGS_MAX*2];
   CCallInfo ci;
   IRRef func;
   IRIns *irf;
@@ -1725,7 +1725,7 @@ static void asm_tail_prep(ASMState *as)
 /* Ensure there are enough stack slots for call arguments. */
 static Reg asm_setup_call_slots(ASMState *as, IRIns *ir, const CCallInfo *ci)
 {
-  IRRef args[CCI_NARGS_MAX];
+  IRRef args[CCI_NARGS_MAX*2];
   uint32_t i, nargs = CCI_XNARGS(ci);
   int nslots = 4, ngpr = REGARG_NUMGPR, nfpr = REGARG_NUMFPR;
   asm_collectargs(as, ir, ci, args);
diff --git a/src/lj_asm_ppc.h b/src/lj_asm_ppc.h
index a4a35547..1cac6fa9 100644
--- a/src/lj_asm_ppc.h
+++ b/src/lj_asm_ppc.h
@@ -331,7 +331,7 @@ static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
 
 static void asm_callx(ASMState *as, IRIns *ir)
 {
-  IRRef args[CCI_NARGS_MAX];
+  IRRef args[CCI_NARGS_MAX*2];
   CCallInfo ci;
   IRRef func;
   IRIns *irf;
@@ -1916,7 +1916,7 @@ static void asm_tail_prep(ASMState *as)
 /* Ensure there are enough stack slots for call arguments. */
 static Reg asm_setup_call_slots(ASMState *as, IRIns *ir, const CCallInfo *ci)
 {
-  IRRef args[CCI_NARGS_MAX];
+  IRRef args[CCI_NARGS_MAX*2];
   uint32_t i, nargs = CCI_XNARGS(ci);
   int nslots = 2, ngpr = REGARG_NUMGPR, nfpr = REGARG_NUMFPR;
   asm_collectargs(as, ir, ci, args);
diff --git a/src/lj_asm_x86.h b/src/lj_asm_x86.h
index 3a029970..25da5246 100644
--- a/src/lj_asm_x86.h
+++ b/src/lj_asm_x86.h
@@ -600,7 +600,7 @@ static void *asm_callx_func(ASMState *as, IRIns *irf, IRRef func)
 
 static void asm_callx(ASMState *as, IRIns *ir)
 {
-  IRRef args[CCI_NARGS_MAX];
+  IRRef args[CCI_NARGS_MAX*2];
   CCallInfo ci;
   IRRef func;
   IRIns *irf;
@@ -2593,7 +2593,7 @@ static void asm_tail_prep(ASMState *as)
 /* Ensure there are enough stack slots for call arguments. */
 static Reg asm_setup_call_slots(ASMState *as, IRIns *ir, const CCallInfo *ci)
 {
-  IRRef args[CCI_NARGS_MAX];
+  IRRef args[CCI_NARGS_MAX*2];
   int nslots;
   asm_collectargs(as, ir, ci, args);
   nslots = asm_count_call_slots(as, ci, args);