diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp
index bb12f9ac7c..5ed00d451f 100644
--- a/src/core/hle/kernel/svc.cpp
+++ b/src/core/hle/kernel/svc.cpp
@@ -1744,11 +1744,51 @@ static ResultCode GetThreadCoreMask(Core::System& system, Handle thread_handle,
 }
 
 static ResultCode SetThreadCoreMask(Core::System& system, Handle thread_handle, u32 core,
-                                    u64 mask) {
-    LOG_DEBUG(Kernel_SVC, "called, handle=0x{:08X}, mask=0x{:016X}, core=0x{:X}", thread_handle,
-              mask, core);
+                                    u64 affinity_mask) {
+    LOG_DEBUG(Kernel_SVC, "called, handle=0x{:08X}, core=0x{:X}, affinity_mask=0x{:016X}",
+              thread_handle, core, affinity_mask);
 
-    const auto& handle_table = system.Kernel().CurrentProcess()->GetHandleTable();
+    const auto* const current_process = system.Kernel().CurrentProcess();
+
+    if (core == static_cast<u32>(THREADPROCESSORID_IDEAL)) {
+        const u8 ideal_cpu_core = current_process->GetIdealCore();
+
+        ASSERT(ideal_cpu_core != static_cast<u8>(THREADPROCESSORID_IDEAL));
+
+        // Set the target CPU to the ideal core specified by the process.
+        core = ideal_cpu_core;
+        affinity_mask = 1ULL << core;
+    } else {
+        const u64 core_mask = current_process->GetCoreMask();
+
+        if ((core_mask | affinity_mask) != core_mask) {
+            LOG_ERROR(
+                Kernel_SVC,
+                "Invalid processor ID specified (core_mask=0x{:08X}, affinity_mask=0x{:016X})",
+                core_mask, affinity_mask);
+            return ERR_INVALID_PROCESSOR_ID;
+        }
+
+        if (affinity_mask == 0) {
+            LOG_ERROR(Kernel_SVC, "Specfified affinity mask is zero.");
+            return ERR_INVALID_COMBINATION;
+        }
+
+        if (core < Core::NUM_CPU_CORES) {
+            if ((affinity_mask & (1ULL << core)) == 0) {
+                LOG_ERROR(Kernel_SVC,
+                          "Core is not enabled for the current mask, core={}, mask={:016X}", core,
+                          affinity_mask);
+                return ERR_INVALID_COMBINATION;
+            }
+        } else if (core != static_cast<u32>(THREADPROCESSORID_DONT_CARE) &&
+                   core != static_cast<u32>(THREADPROCESSORID_DONT_UPDATE)) {
+            LOG_ERROR(Kernel_SVC, "Invalid processor ID specified (core={}).", core);
+            return ERR_INVALID_PROCESSOR_ID;
+        }
+    }
+
+    const auto& handle_table = current_process->GetHandleTable();
     const SharedPtr<Thread> thread = handle_table.Get<Thread>(thread_handle);
     if (!thread) {
         LOG_ERROR(Kernel_SVC, "Thread handle does not exist, thread_handle=0x{:08X}",
@@ -1756,40 +1796,7 @@ static ResultCode SetThreadCoreMask(Core::System& system, Handle thread_handle,
         return ERR_INVALID_HANDLE;
     }
 
-    if (core == static_cast<u32>(THREADPROCESSORID_IDEAL)) {
-        const u8 ideal_cpu_core = thread->GetOwnerProcess()->GetIdealCore();
-
-        ASSERT(ideal_cpu_core != static_cast<u8>(THREADPROCESSORID_IDEAL));
-
-        // Set the target CPU to the ideal core specified by the process.
-        core = ideal_cpu_core;
-        mask = 1ULL << core;
-    }
-
-    if (mask == 0) {
-        LOG_ERROR(Kernel_SVC, "Mask is 0");
-        return ERR_INVALID_COMBINATION;
-    }
-
-    /// This value is used to only change the affinity mask without changing the current ideal core.
-    static constexpr u32 OnlyChangeMask = static_cast<u32>(-3);
-
-    if (core == OnlyChangeMask) {
-        core = thread->GetIdealCore();
-    } else if (core >= Core::NUM_CPU_CORES && core != static_cast<u32>(THREADPROCESSORID_DONT_UPDATE)) {
-        LOG_ERROR(Kernel_SVC, "Invalid core specified, got {}", core);
-        return ERR_INVALID_PROCESSOR_ID;
-    }
-
-    // Error out if the input core isn't enabled in the input mask.
-    if (core < Core::NUM_CPU_CORES && (mask & (1ull << core)) == 0) {
-        LOG_ERROR(Kernel_SVC, "Core is not enabled for the current mask, core={}, mask={:016X}",
-                  core, mask);
-        return ERR_INVALID_COMBINATION;
-    }
-
-    thread->ChangeCore(core, mask);
-
+    thread->ChangeCore(core, affinity_mask);
     return RESULT_SUCCESS;
 }