diff --git a/src/backend_x64/emit_x64.cpp b/src/backend_x64/emit_x64.cpp
index c991a739..085bce5a 100644
--- a/src/backend_x64/emit_x64.cpp
+++ b/src/backend_x64/emit_x64.cpp
@@ -325,17 +325,16 @@ void EmitX64::EmitSetVFlag(RegAlloc& reg_alloc, IR::Block&, IR::Inst* inst) {
 }
 
 void EmitX64::EmitOrQFlag(RegAlloc& reg_alloc, IR::Block&, IR::Inst* inst) {
-    constexpr size_t flag_bit = 27;
-    constexpr u32 flag_mask = 1u << flag_bit;
+    using namespace Xbyak::util;
+
     auto args = reg_alloc.GetArgumentInfo(inst);
     if (args[0].IsImmediate()) {
         if (args[0].GetImmediateU1())
-            code->or_(MJitStateCpsr_other(), flag_mask);
+            code->mov(dword[r15 + offsetof(JitState, CPSR_q)], 1);
     } else {
-        Xbyak::Reg32 to_store = reg_alloc.UseScratchGpr(args[0]).cvt32();
+        Xbyak::Reg8 to_store = reg_alloc.UseGpr(args[0]).cvt8();
 
-        code->shl(to_store, flag_bit);
-        code->or_(MJitStateCpsr_other(), to_store);
+        code->or_(code->byte[r15 + offsetof(JitState, CPSR_q)], to_store);
     }
 }
 
diff --git a/src/backend_x64/jitstate.cpp b/src/backend_x64/jitstate.cpp
index 715f77a8..9898a3d8 100644
--- a/src/backend_x64/jitstate.cpp
+++ b/src/backend_x64/jitstate.cpp
@@ -47,6 +47,8 @@ namespace BackendX64 {
 u32 JitState::Cpsr() const {
     u32 cpsr = 0;
 
+    // Q flag
+    cpsr |= CPSR_q ? 1 << 27 : 0;
     // GE flags
     cpsr |= Common::Bit<31>(CPSR_ge) ? 1 << 19 : 0;
     cpsr |= Common::Bit<23>(CPSR_ge) ? 1 << 18 : 0;
@@ -62,6 +64,8 @@ u32 JitState::Cpsr() const {
 }
 
 void JitState::SetCpsr(u32 cpsr) {
+    // Q flag
+    CPSR_q = Common::Bit<27>(cpsr) ? 1 : 0;
     // GE flags
     CPSR_ge = 0;
     CPSR_ge |= Common::Bit<19>(cpsr) ? 0xFF000000 : 0;
@@ -73,7 +77,7 @@ void JitState::SetCpsr(u32 cpsr) {
     CPSR_et |= Common::Bit<9>(cpsr) ? 2 : 0;
     CPSR_et |= Common::Bit<5>(cpsr) ? 1 : 0;
     // Other flags
-    CPSR_other = cpsr & 0xFFF0FDDF;
+    CPSR_other = cpsr & 0xF7F0FDDF;
 }
 
 void JitState::ResetRSB() {
diff --git a/src/backend_x64/jitstate.h b/src/backend_x64/jitstate.h
index 911cdb2b..3695b8e8 100644
--- a/src/backend_x64/jitstate.h
+++ b/src/backend_x64/jitstate.h
@@ -31,6 +31,7 @@ struct JitState {
     u32 CPSR_other = 0;
     u32 CPSR_ge = 0;
     u32 CPSR_et = 0;
+    u32 CPSR_q = 0;
     u32 Cpsr() const;
     void SetCpsr(u32 cpsr);