diff --git a/src/lj_asm.c b/src/lj_asm.c
index 038f4d1c..316e81d6 100644
--- a/src/lj_asm.c
+++ b/src/lj_asm.c
@@ -948,7 +948,7 @@ static void asm_collectargs(ASMState *as, IRIns *ir,
 			    const CCallInfo *ci, IRRef *args)
 {
   uint32_t n = CCI_NARGS(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 7c5f7188..a66573c0 100644
--- a/src/lj_asm_arm.h
+++ b/src/lj_asm_arm.h
@@ -464,7 +464,7 @@ static void asm_call(ASMState *as, IRIns *ir)
 
 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;
@@ -2295,7 +2295,7 @@ static void asm_ir(ASMState *as, IRIns *ir)
 /* 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 = (int)CCI_NARGS(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 7d1a8c68..9fe7c9c3 100644
--- a/src/lj_asm_mips.h
+++ b/src/lj_asm_mips.h
@@ -337,7 +337,7 @@ static void asm_call(ASMState *as, IRIns *ir)
 
 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;
@@ -1894,7 +1894,7 @@ static void asm_ir(ASMState *as, IRIns *ir)
 /* 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 = (int)CCI_NARGS(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 34bd721f..651fa318 100644
--- a/src/lj_asm_ppc.h
+++ b/src/lj_asm_ppc.h
@@ -340,7 +340,7 @@ static void asm_call(ASMState *as, IRIns *ir)
 
 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;
@@ -2092,7 +2092,7 @@ static void asm_ir(ASMState *as, IRIns *ir)
 /* 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 = (int)CCI_NARGS(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 8bae1789..64441ccb 100644
--- a/src/lj_asm_x86.h
+++ b/src/lj_asm_x86.h
@@ -609,7 +609,7 @@ 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;
@@ -2742,7 +2742,7 @@ static void asm_ir(ASMState *as, IRIns *ir)
 /* 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);