diff --git a/Source/UnitTests/Core/PageFaultTest.cpp b/Source/UnitTests/Core/PageFaultTest.cpp
index ab0cdd7bcc..3f693923e0 100644
--- a/Source/UnitTests/Core/PageFaultTest.cpp
+++ b/Source/UnitTests/Core/PageFaultTest.cpp
@@ -5,7 +5,9 @@
 #include <fmt/format.h>
 
 #include "Common/CommonTypes.h"
+#include "Common/ScopeGuard.h"
 #include "Common/Timer.h"
+#include "Core/Core.h"
 #include "Core/MemTools.h"
 #include "Core/PowerPC/JitCommon/JitBase.h"
 #include "Core/PowerPC/JitInterface.h"
@@ -75,6 +77,9 @@ TEST(PageFault, PageFault)
   EXPECT_NE(data, nullptr);
   Common::WriteProtectMemory(data, PAGE_GRAN, false);
 
+  Core::DeclareAsCPUThread();
+  Common::ScopeGuard cpu_thread_guard([] { Core::UndeclareAsCPUThread(); });
+
   auto& system = Core::System::GetInstance();
   auto unique_pfjit = std::make_unique<PageFaultFakeJit>(system);
   auto& pfjit = *unique_pfjit;
diff --git a/Source/UnitTests/Core/PowerPC/Jit64Common/ConvertDoubleToSingle.cpp b/Source/UnitTests/Core/PowerPC/Jit64Common/ConvertDoubleToSingle.cpp
index bbf6445357..09c0f30169 100644
--- a/Source/UnitTests/Core/PowerPC/Jit64Common/ConvertDoubleToSingle.cpp
+++ b/Source/UnitTests/Core/PowerPC/Jit64Common/ConvertDoubleToSingle.cpp
@@ -5,7 +5,9 @@
 #include <tuple>
 
 #include "Common/CommonTypes.h"
+#include "Common/ScopeGuard.h"
 #include "Common/x64ABI.h"
+#include "Core/Core.h"
 #include "Core/PowerPC/Gekko.h"
 #include "Core/PowerPC/Interpreter/Interpreter_FPUtils.h"
 #include "Core/PowerPC/Jit64/Jit.h"
@@ -52,6 +54,9 @@ public:
 
 TEST(Jit64, ConvertDoubleToSingle)
 {
+  Core::DeclareAsCPUThread();
+  Common::ScopeGuard cpu_thread_guard([] { Core::UndeclareAsCPUThread(); });
+
   TestCommonAsmRoutines routines(Core::System::GetInstance());
 
   for (const u64 input : double_test_values)
diff --git a/Source/UnitTests/Core/PowerPC/Jit64Common/Frsqrte.cpp b/Source/UnitTests/Core/PowerPC/Jit64Common/Frsqrte.cpp
index d0ce6b3653..3300c07541 100644
--- a/Source/UnitTests/Core/PowerPC/Jit64Common/Frsqrte.cpp
+++ b/Source/UnitTests/Core/PowerPC/Jit64Common/Frsqrte.cpp
@@ -6,7 +6,9 @@
 #include "Common/BitUtils.h"
 #include "Common/CommonTypes.h"
 #include "Common/FloatUtils.h"
+#include "Common/ScopeGuard.h"
 #include "Common/x64ABI.h"
+#include "Core/Core.h"
 #include "Core/PowerPC/Gekko.h"
 #include "Core/PowerPC/Jit64/Jit.h"
 #include "Core/PowerPC/Jit64Common/Jit64AsmCommon.h"
@@ -59,6 +61,9 @@ public:
 
 TEST(Jit64, Frsqrte)
 {
+  Core::DeclareAsCPUThread();
+  Common::ScopeGuard cpu_thread_guard([] { Core::UndeclareAsCPUThread(); });
+
   TestCommonAsmRoutines routines(Core::System::GetInstance());
 
   UReg_FPSCR fpscr;
diff --git a/Source/UnitTests/Core/PowerPC/JitArm64/ConvertSingleDouble.cpp b/Source/UnitTests/Core/PowerPC/JitArm64/ConvertSingleDouble.cpp
index 0e87fddcda..588a1622ef 100644
--- a/Source/UnitTests/Core/PowerPC/JitArm64/ConvertSingleDouble.cpp
+++ b/Source/UnitTests/Core/PowerPC/JitArm64/ConvertSingleDouble.cpp
@@ -7,6 +7,8 @@
 #include "Common/BitUtils.h"
 #include "Common/CommonTypes.h"
 #include "Common/FPURoundMode.h"
+#include "Common/ScopeGuard.h"
+#include "Core/Core.h"
 #include "Core/PowerPC/Interpreter/Interpreter_FPUtils.h"
 #include "Core/PowerPC/JitArm64/Jit.h"
 #include "Core/System.h"
@@ -120,6 +122,9 @@ private:
 
 TEST(JitArm64, ConvertDoubleToSingle)
 {
+  Core::DeclareAsCPUThread();
+  Common::ScopeGuard cpu_thread_guard([] { Core::UndeclareAsCPUThread(); });
+
   TestConversion test(Core::System::GetInstance());
 
   for (const u64 input : double_test_values)
@@ -155,6 +160,9 @@ TEST(JitArm64, ConvertDoubleToSingle)
 
 TEST(JitArm64, ConvertSingleToDouble)
 {
+  Core::DeclareAsCPUThread();
+  Common::ScopeGuard cpu_thread_guard([] { Core::UndeclareAsCPUThread(); });
+
   TestConversion test(Core::System::GetInstance());
 
   for (const u32 input : single_test_values)
diff --git a/Source/UnitTests/Core/PowerPC/JitArm64/FPRF.cpp b/Source/UnitTests/Core/PowerPC/JitArm64/FPRF.cpp
index 285469b90f..0b7e250ae6 100644
--- a/Source/UnitTests/Core/PowerPC/JitArm64/FPRF.cpp
+++ b/Source/UnitTests/Core/PowerPC/JitArm64/FPRF.cpp
@@ -7,6 +7,8 @@
 #include "Common/Arm64Emitter.h"
 #include "Common/BitUtils.h"
 #include "Common/CommonTypes.h"
+#include "Common/ScopeGuard.h"
+#include "Core/Core.h"
 #include "Core/PowerPC/Interpreter/Interpreter_FPUtils.h"
 #include "Core/PowerPC/JitArm64/Jit.h"
 #include "Core/PowerPC/PowerPC.h"
@@ -70,6 +72,9 @@ static u32 RunUpdateFPRF(PowerPC::PowerPCState& ppc_state, const std::function<v
 
 TEST(JitArm64, FPRF)
 {
+  Core::DeclareAsCPUThread();
+  Common::ScopeGuard cpu_thread_guard([] { Core::UndeclareAsCPUThread(); });
+
   auto& system = Core::System::GetInstance();
   auto& ppc_state = system.GetPPCState();
   TestFPRF test(system);
diff --git a/Source/UnitTests/Core/PowerPC/JitArm64/Fres.cpp b/Source/UnitTests/Core/PowerPC/JitArm64/Fres.cpp
index d2624f117d..3df9a6c964 100644
--- a/Source/UnitTests/Core/PowerPC/JitArm64/Fres.cpp
+++ b/Source/UnitTests/Core/PowerPC/JitArm64/Fres.cpp
@@ -6,6 +6,8 @@
 #include "Common/Arm64Emitter.h"
 #include "Common/BitUtils.h"
 #include "Common/CommonTypes.h"
+#include "Common/ScopeGuard.h"
+#include "Core/Core.h"
 #include "Core/PowerPC/Interpreter/Interpreter_FPUtils.h"
 #include "Core/PowerPC/JitArm64/Jit.h"
 #include "Core/PowerPC/PowerPC.h"
@@ -51,6 +53,9 @@ public:
 
 TEST(JitArm64, Fres)
 {
+  Core::DeclareAsCPUThread();
+  Common::ScopeGuard cpu_thread_guard([] { Core::UndeclareAsCPUThread(); });
+
   TestFres test(Core::System::GetInstance());
 
   for (const u64 ivalue : double_test_values)
diff --git a/Source/UnitTests/Core/PowerPC/JitArm64/Frsqrte.cpp b/Source/UnitTests/Core/PowerPC/JitArm64/Frsqrte.cpp
index cf5bfd0df0..ca5e36653b 100644
--- a/Source/UnitTests/Core/PowerPC/JitArm64/Frsqrte.cpp
+++ b/Source/UnitTests/Core/PowerPC/JitArm64/Frsqrte.cpp
@@ -6,6 +6,8 @@
 #include "Common/Arm64Emitter.h"
 #include "Common/BitUtils.h"
 #include "Common/CommonTypes.h"
+#include "Common/ScopeGuard.h"
+#include "Core/Core.h"
 #include "Core/PowerPC/Interpreter/Interpreter_FPUtils.h"
 #include "Core/PowerPC/JitArm64/Jit.h"
 #include "Core/PowerPC/PowerPC.h"
@@ -51,6 +53,9 @@ public:
 
 TEST(JitArm64, Frsqrte)
 {
+  Core::DeclareAsCPUThread();
+  Common::ScopeGuard cpu_thread_guard([] { Core::UndeclareAsCPUThread(); });
+
   TestFrsqrte test(Core::System::GetInstance());
 
   for (const u64 ivalue : double_test_values)