diff --git a/ipc/glue/BackgroundImpl.cpp b/ipc/glue/BackgroundImpl.cpp
index 9434aea02427..5e6166d2268a 100644
--- a/ipc/glue/BackgroundImpl.cpp
+++ b/ipc/glue/BackgroundImpl.cpp
@@ -318,7 +318,9 @@ class ChildImpl final : public BackgroundChildImpl
   struct ThreadLocalInfo
   {
     explicit ThreadLocalInfo(nsIIPCBackgroundChildCreateCallback* aCallback)
+#ifdef DEBUG
       : mClosed(false)
+#endif
     {
       mCallbacks.AppendElement(aCallback);
     }
@@ -326,7 +328,9 @@ class ChildImpl final : public BackgroundChildImpl
     RefPtr<ChildImpl> mActor;
     nsTArray<nsCOMPtr<nsIIPCBackgroundChildCreateCallback>> mCallbacks;
     nsAutoPtr<BackgroundChildImpl::ThreadLocal> mConsumerThreadLocal;
-    DebugOnly<bool> mClosed;
+#ifdef DEBUG
+    bool mClosed;
+#endif
   };
 
   // This is only modified on the main thread. It is a FIFO queue for actors
@@ -338,12 +342,16 @@ class ChildImpl final : public BackgroundChildImpl
   static bool sShutdownHasStarted;
 
 #ifdef RELEASE_BUILD
-  DebugOnly<nsIThread*> mBoundThread;
+#ifdef DEBUG
+  nsIThread* mBoundThread;
+#endif
 #else
   nsIThread* mBoundThread;
 #endif
 
-  DebugOnly<bool> mActorDestroyed;
+#ifdef DEBUG
+  bool mActorDestroyed;
+#endif
 
 public:
   static bool
@@ -375,7 +383,9 @@ public:
 
   ChildImpl()
   : mBoundThread(nullptr)
+#ifdef DEBUG
   , mActorDestroyed(false)
+#endif
   {
     AssertIsOnMainThread();
   }
@@ -1612,6 +1622,7 @@ ChildImpl::Shutdown()
 
   sShutdownHasStarted = true;
 
+#ifdef DEBUG
   MOZ_ASSERT(sThreadLocalIndex != kBadThreadLocalIndex);
 
   auto threadLocalInfo =
@@ -1621,6 +1632,7 @@ ChildImpl::Shutdown()
     MOZ_ASSERT(!threadLocalInfo->mClosed);
     threadLocalInfo->mClosed = true;
   }
+#endif
 
   DebugOnly<PRStatus> status = PR_SetThreadPrivate(sThreadLocalIndex, nullptr);
   MOZ_ASSERT(status == PR_SUCCESS);
@@ -1747,8 +1759,10 @@ ChildImpl::CloseForCurrentThread()
     return;
   }
 
+#ifdef DEBUG
   MOZ_ASSERT(!threadLocalInfo->mClosed);
   threadLocalInfo->mClosed = true;
+#endif
 
   if (threadLocalInfo->mActor) {
     threadLocalInfo->mActor->FlushPendingInterruptQueue();
@@ -2092,8 +2106,10 @@ ChildImpl::ActorDestroy(ActorDestroyReason aWhy)
 {
   AssertIsOnBoundThread();
 
+#ifdef DEBUG
   MOZ_ASSERT(!mActorDestroyed);
   mActorDestroyed = true;
+#endif
 
   BackgroundChildImpl::ActorDestroy(aWhy);
 }
diff --git a/ipc/glue/FileDescriptor.cpp b/ipc/glue/FileDescriptor.cpp
index dd8dbba1cd8a..e9d6ba2a0b54 100644
--- a/ipc/glue/FileDescriptor.cpp
+++ b/ipc/glue/FileDescriptor.cpp
@@ -29,13 +29,17 @@
 using mozilla::ipc::FileDescriptor;
 
 FileDescriptor::FileDescriptor()
-: mHandle(INVALID_HANDLE), mHandleCreatedByOtherProcess(false),
-  mHandleCreatedByOtherProcessWasUsed(false)
+  : mHandle(INVALID_HANDLE), mHandleCreatedByOtherProcess(false)
+#ifdef DEBUG
+  , mHandleCreatedByOtherProcessWasUsed(false)
+#endif
 { }
 
 FileDescriptor::FileDescriptor(PlatformHandleType aHandle)
-: mHandle(INVALID_HANDLE), mHandleCreatedByOtherProcess(false),
-  mHandleCreatedByOtherProcessWasUsed(false)
+  : mHandle(INVALID_HANDLE), mHandleCreatedByOtherProcess(false)
+#ifdef DEBUG
+  , mHandleCreatedByOtherProcessWasUsed(false)
+#endif
 {
   DuplicateInCurrentProcess(aHandle);
 }
diff --git a/ipc/glue/FileDescriptor.h b/ipc/glue/FileDescriptor.h
index 8d94351d42ab..16e180ad4e5d 100644
--- a/ipc/glue/FileDescriptor.h
+++ b/ipc/glue/FileDescriptor.h
@@ -52,8 +52,10 @@ public:
   FileDescriptor();
 
   FileDescriptor(const FileDescriptor& aOther)
-    : mHandleCreatedByOtherProcess(false),
-      mHandleCreatedByOtherProcessWasUsed(false)
+    : mHandleCreatedByOtherProcess(false)
+#ifdef DEBUG
+    , mHandleCreatedByOtherProcessWasUsed(false)
+#endif
   {
     // Don't use operator= here because that will call
     // CloseCurrentProcessHandle() on this (uninitialized) object.
@@ -69,7 +71,9 @@ public:
   : mHandle(aPickle.fd)
 #endif
   , mHandleCreatedByOtherProcess(true)
+#ifdef DEBUG
   , mHandleCreatedByOtherProcessWasUsed(false)
+#endif
   { }
 
   ~FileDescriptor()
@@ -102,9 +106,11 @@ public:
   PlatformHandleType
   PlatformHandle() const
   {
+#ifdef DEBUG
     if (mHandleCreatedByOtherProcess) {
       mHandleCreatedByOtherProcessWasUsed = true;
     }
+#endif
     return mHandle;
   }
 
@@ -120,13 +126,17 @@ private:
   {
     if (aOther.mHandleCreatedByOtherProcess) {
       mHandleCreatedByOtherProcess = true;
+#ifdef DEBUG
       mHandleCreatedByOtherProcessWasUsed =
         aOther.mHandleCreatedByOtherProcessWasUsed;
+#endif
       mHandle = aOther.PlatformHandle();
     } else {
       DuplicateInCurrentProcess(aOther.PlatformHandle());
       mHandleCreatedByOtherProcess = false;
+#ifdef DEBUG
       mHandleCreatedByOtherProcessWasUsed = false;
+#endif
     }
   }
 
@@ -147,9 +157,11 @@ private:
   // destruction.
   bool mHandleCreatedByOtherProcess;
 
+#ifdef DEBUG
   // This is to ensure that we don't leak the handle (which is only possible
   // when we're in the receiving process).
-  mutable DebugOnly<bool> mHandleCreatedByOtherProcessWasUsed;
+  mutable bool mHandleCreatedByOtherProcessWasUsed;
+#endif
 };
 
 } // namespace ipc
diff --git a/ipc/glue/MessagePump.cpp b/ipc/glue/MessagePump.cpp
index a7b62a95e3ad..23ce47d29c90 100644
--- a/ipc/glue/MessagePump.cpp
+++ b/ipc/glue/MessagePump.cpp
@@ -32,7 +32,9 @@ using namespace mozilla::ipc;
 
 NS_DEFINE_NAMED_CID(NS_TIMER_CID);
 
-static mozilla::DebugOnly<MessagePump::Delegate*> gFirstDelegate;
+#ifdef DEBUG
+static MessagePump::Delegate* gFirstDelegate;
+#endif
 
 namespace mozilla {
 namespace ipc {
@@ -253,7 +255,9 @@ MessagePumpForChildProcess::Run(base::MessagePump::Delegate* aDelegate)
 {
   if (mFirstRun) {
     MOZ_ASSERT(aDelegate && !gFirstDelegate);
+#ifdef DEBUG
     gFirstDelegate = aDelegate;
+#endif
 
     mFirstRun = false;
     if (NS_FAILED(XRE_RunAppShell())) {
@@ -261,7 +265,9 @@ MessagePumpForChildProcess::Run(base::MessagePump::Delegate* aDelegate)
     }
 
     MOZ_ASSERT(aDelegate && aDelegate == gFirstDelegate);
+#ifdef DEBUG
     gFirstDelegate = nullptr;
+#endif
 
     return;
   }