diff --git a/src/coreclr/vm/ceemain.cpp b/src/coreclr/vm/ceemain.cpp
index e1c06d2c629797..188cdb9abd50b4 100644
--- a/src/coreclr/vm/ceemain.cpp
+++ b/src/coreclr/vm/ceemain.cpp
@@ -470,6 +470,7 @@ void InitGSCookie()
 
     volatile GSCookie * pGSCookiePtr = GetProcessGSCookiePtr();
 
+#ifdef FEATURE_READONLY_GS_COOKIE
     // The GS cookie is stored in a read only data segment
     DWORD oldProtection;
     if(!ClrVirtualProtect((LPVOID)pGSCookiePtr, sizeof(GSCookie), PAGE_READWRITE, &oldProtection))
@@ -481,6 +482,7 @@ void InitGSCookie()
     // PAL layer is unable to extract old protection for regions that were not allocated using VirtualAlloc
     oldProtection = PAGE_READONLY;
 #endif // TARGET_UNIX
+#endif // FEATURE_READONLY_GS_COOKIE
 
 #ifndef TARGET_UNIX
     // The GSCookie cannot be in a writeable page
@@ -507,10 +509,12 @@ void InitGSCookie()
         val ++;
     *pGSCookiePtr = val;
 
+#ifdef FEATURE_READONLY_GS_COOKIE
     if(!ClrVirtualProtect((LPVOID)pGSCookiePtr, sizeof(GSCookie), oldProtection, &oldProtection))
     {
         ThrowLastError();
     }
+#endif // FEATURE_READONLY_GS_COOKIE
 }
 
 Volatile<BOOL> g_bIsGarbageCollectorFullyInitialized = FALSE;
diff --git a/src/coreclr/vm/vars.cpp b/src/coreclr/vm/vars.cpp
index 57046ff71c5a8b..ae813d80f56c72 100644
--- a/src/coreclr/vm/vars.cpp
+++ b/src/coreclr/vm/vars.cpp
@@ -252,7 +252,11 @@ void OBJECTREF_EnumMemoryRegions(OBJECTREF ref)
 //
 // We need the following to be the compiler's notion of volatile.
 //
+#ifdef FEATURE_READONLY_GS_COOKIE
 extern "C" RAW_KEYWORD(volatile) const GSCookie s_gsCookie = 0;
+#else
+extern "C" RAW_KEYWORD(volatile) GSCookie s_gsCookie = 0;
+#endif
 
 #else
 __GlobalVal< GSCookie > s_gsCookie(&DacGlobals::dac__s_gsCookie);
diff --git a/src/coreclr/vm/vars.hpp b/src/coreclr/vm/vars.hpp
index 6960585b9e7482..d78923ae1d06c2 100644
--- a/src/coreclr/vm/vars.hpp
+++ b/src/coreclr/vm/vars.hpp
@@ -593,12 +593,22 @@ typedef DPTR(GSCookie) PTR_GSCookie;
 #define READONLY_ATTR __attribute__((READONLY_ATTR_ARGS))
 #endif
 
+// Apple's __DATA_CONST segment is immutable at runtime, so InitGSCookie's ClrVirtualProtect
+// call fails there (see nativeaot/Runtime for the same FEATURE_READONLY_GS_COOKIE guard).
+#ifndef TARGET_APPLE
+#define FEATURE_READONLY_GS_COOKIE
+#endif
+
 #ifndef DACCESS_COMPILE
 // const is so that it gets placed in the .text section (which is read-only)
 // volatile is so that accesses to it do not get optimized away because of the const
 //
 
+#ifdef FEATURE_READONLY_GS_COOKIE
 extern "C" RAW_KEYWORD(volatile) READONLY_ATTR const GSCookie s_gsCookie;
+#else
+extern "C" RAW_KEYWORD(volatile) GSCookie s_gsCookie;
+#endif
 
 inline
 GSCookie * GetProcessGSCookiePtr() { return  const_cast<GSCookie *>(&s_gsCookie); }