diff --git a/GPU/GPUTracking/Definitions/GPUSettingsList.h b/GPU/GPUTracking/Definitions/GPUSettingsList.h
index 4e3e0cd32d752..81949f0b8ed2a 100644
--- a/GPU/GPUTracking/Definitions/GPUSettingsList.h
+++ b/GPU/GPUTracking/Definitions/GPUSettingsList.h
@@ -221,7 +221,7 @@ AddSubConfig(GPUSettingsRecDynamic, dyn)
 AddHelp("help", 'h')
 EndConfig()
 
-#ifndef __OPENCL__
+#if !defined(__OPENCL__) && !defined(__METAL__) // these use std::string / std::vector, which device code does not have
 // Parameters that might affect the RTC code (if these change, the cache cannot be used)
 BeginSubConfig(GPUSettingsProcessingRTC, rtc, configStandalone.proc, "RTC", 0, "Processing settings", proc_rtc)
 AddOption(cacheOutput, bool, false, "", 0, "Cache RTC compilation results")
@@ -428,7 +428,7 @@ AddSubConfig(GPUSettingsProcessingNNclusterizer, nn)
 AddSubConfig(GPUSettingsProcessingScaling, scaling)
 AddHelp("help", 'h')
 EndConfig()
-#endif // __OPENCL__
+#endif // !__OPENCL__ && !__METAL__
 
 #ifndef GPUCA_GPUCODE_DEVICE
 // Light settings concerning the event display (can be changed without rebuilding vertices)
diff --git a/GPU/Utils/GPUCommonBitSet.h b/GPU/Utils/GPUCommonBitSet.h
index 302334e01e29d..e35587ab60c7b 100644
--- a/GPU/Utils/GPUCommonBitSet.h
+++ b/GPU/Utils/GPUCommonBitSet.h
@@ -37,7 +37,12 @@ class bitset
 
  public:
   GPUdDefault() constexpr bitset() = default;
+#ifndef __METAL__
+  // MSL will not use a user-declared copy constructor to build an object in the
+  // constant address space, where GPUconstexpr() arrays of bitset live. Leaving
+  // it implicit is what makes those arrays constructible.
   GPUdDefault() constexpr bitset(const bitset&) = default;
+#endif
 #ifdef __OPENCL__
   GPUdDefault() constexpr bitset(const __constant bitset&) = default;
 #endif // __OPENCL__