--- a/xpcom/glue/nsISupportsImpl.h
+++ b/xpcom/glue/nsISupportsImpl.h
@@ -15,19 +15,17 @@
 
 
 #if !defined(XPCOM_GLUE_AVOID_NSPR)
 #include "prthread.h" /* needed for thread-safety checks */
 #endif // !XPCOM_GLUE_AVOID_NSPR
 
 #include "nsDebug.h"
 #include "nsXPCOM.h"
-#ifndef XPCOM_GLUE
 #include "mozilla/Atomics.h"
-#endif
 #include "mozilla/Attributes.h"
 #include "mozilla/Assertions.h"
 #include "mozilla/Compiler.h"
 #include "mozilla/Likely.h"
 #include "mozilla/MacroArgs.h"
 #include "mozilla/MacroForEach.h"
 #include "mozilla/TypeTraits.h"
 
@@ -326,17 +324,16 @@ public:
 
   static const bool isThreadSafe = false;
 private:
   nsrefcnt operator++(int) = delete;
   nsrefcnt operator--(int) = delete;
   nsrefcnt mValue;
 };
 
-#ifndef XPCOM_GLUE
 namespace mozilla {
 class ThreadSafeAutoRefCnt
 {
 public:
   ThreadSafeAutoRefCnt() : mValue(0) {}
   explicit ThreadSafeAutoRefCnt(nsrefcnt aValue) : mValue(aValue) {}
 
   // only support prefix increment/decrement
@@ -355,17 +352,16 @@ private:
   nsrefcnt operator++(int) = delete;
   nsrefcnt operator--(int) = delete;
   // In theory, RelaseAcquire consistency (but no weaker) is sufficient for
   // the counter. Making it weaker could speed up builds on ARM (but not x86),
   // but could break pre-existing code that assumes sequential consistency.
   Atomic<nsrefcnt> mValue;
 };
 } // namespace mozilla
-#endif
 
 ///////////////////////////////////////////////////////////////////////////////
 
 /**
  * Declare the reference count variable and the implementations of the
  * AddRef and QueryInterface methods.
  */