diff --git a/src/backend_x64/hostloc.cpp b/src/backend_x64/hostloc.cpp
index 3de11ca3..bc1683af 100644
--- a/src/backend_x64/hostloc.cpp
+++ b/src/backend_x64/hostloc.cpp
@@ -24,7 +24,7 @@ Xbyak::Xmm HostLocToXmm(HostLoc loc) {
 Xbyak::Address SpillToOpArg(HostLoc loc) {
     using namespace Xbyak::util;
 
-    static_assert(std::is_same<decltype(JitState{nullptr}.Spill[0]), u64&>::value, "Spill must be u64");
+    static_assert(std::is_same<decltype(JitState::Spill[0]), u64&>::value, "Spill must be u64");
     DEBUG_ASSERT(HostLocIsSpill(loc));
 
     size_t i = static_cast<size_t>(loc) - static_cast<size_t>(HostLoc::FirstSpill);