diff --git a/External/FEXCore/Source/Interface/HLE/x64/Syscalls.cpp b/External/FEXCore/Source/Interface/HLE/x64/Syscalls.cpp
index ad06c1d19..666f2768d 100644
--- a/External/FEXCore/Source/Interface/HLE/x64/Syscalls.cpp
+++ b/External/FEXCore/Source/Interface/HLE/x64/Syscalls.cpp
@@ -20,8 +20,8 @@
 #include "LogManager.h"
 
 namespace {
-  uint64_t Unimplemented(FEXCore::Core::InternalThreadState *Thread) {
-    ERROR_AND_DIE("Unhandled system call");
+  uint64_t Unimplemented(FEXCore::Core::InternalThreadState *Thread, uint64_t SyscallNumber) {
+    ERROR_AND_DIE("Unhandled system call: %d", SyscallNumber);
     return -1;
   }
 
@@ -750,7 +750,7 @@ void x64SyscallHandler::RegisterSyscallHandlers() {
 
   // Clear all definitions
   for (auto &Def : Definitions) {
-    Def.NumArgs = 0;
+    Def.NumArgs = 255;
     Def.Ptr = cvt(&Unimplemented);
   }
 
@@ -947,6 +947,8 @@ uint64_t x64SyscallHandler::HandleSyscall(FEXCore::Core::InternalThreadState *Th
   case 4: return std::invoke(Def.Ptr4, Thread, Args->Argument[1], Args->Argument[2], Args->Argument[3], Args->Argument[4]);
   case 5: return std::invoke(Def.Ptr5, Thread, Args->Argument[1], Args->Argument[2], Args->Argument[3], Args->Argument[4], Args->Argument[5]);
   case 6: return std::invoke(Def.Ptr6, Thread, Args->Argument[1], Args->Argument[2], Args->Argument[3], Args->Argument[4], Args->Argument[5], Args->Argument[6]);
+  // for missing syscalls
+  case 255: return std::invoke(Def.Ptr1, Thread, Args->Argument[0]);
   default: break;
   }