diff --git a/netwerk/base/EventTokenBucket.cpp b/netwerk/base/EventTokenBucket.cpp
index 22b7dc0d6ae9..d6696a979333 100644
--- a/netwerk/base/EventTokenBucket.cpp
+++ b/netwerk/base/EventTokenBucket.cpp
@@ -19,8 +19,6 @@
 #include <mmsystem.h>
 #endif
 
-extern PRThread *gSocketThread;
-
 namespace mozilla {
 namespace net {
 
diff --git a/netwerk/base/TLSServerSocket.cpp b/netwerk/base/TLSServerSocket.cpp
index cbdb5ce680cd..5d9046f901a7 100644
--- a/netwerk/base/TLSServerSocket.cpp
+++ b/netwerk/base/TLSServerSocket.cpp
@@ -20,8 +20,6 @@
 #include "ScopedNSSTypes.h"
 #include "ssl.h"
 
-extern PRThread *gSocketThread;
-
 namespace mozilla {
 namespace net {
 
diff --git a/netwerk/base/nsSocketTransportService2.cpp b/netwerk/base/nsSocketTransportService2.cpp
index 06ec9b6a2601..491c9a0c5db8 100644
--- a/netwerk/base/nsSocketTransportService2.cpp
+++ b/netwerk/base/nsSocketTransportService2.cpp
@@ -17,6 +17,7 @@
 #include "nsIPrefBranch.h"
 #include "nsServiceManagerUtils.h"
 #include "nsIObserverService.h"
+#include "mozilla/Atomics.h"
 #include "mozilla/Services.h"
 #include "mozilla/Likely.h"
 #include "mozilla/PublicSSL.h"
@@ -33,7 +34,7 @@ LazyLogModule gSocketTransportLog("nsSocketTransport");
 LazyLogModule gUDPSocketLog("UDPSocket");
 
 nsSocketTransportService *gSocketTransportService = nullptr;
-PRThread                 *gSocketThread           = nullptr;
+Atomic<PRThread*, Relaxed> gSocketThread;
 
 #define SEND_BUFFER_PREF "network.tcp.sendbuffer"
 #define KEEPALIVE_ENABLED_PREF "network.tcp.keepalive.enabled"
diff --git a/netwerk/base/nsSocketTransportService2.h b/netwerk/base/nsSocketTransportService2.h
index 578ad14eb8d1..6da694b309ae 100644
--- a/netwerk/base/nsSocketTransportService2.h
+++ b/netwerk/base/nsSocketTransportService2.h
@@ -262,6 +262,6 @@ private:
 };
 
 extern nsSocketTransportService *gSocketTransportService;
-extern PRThread                 *gSocketThread;
+extern mozilla::Atomic<PRThread*, mozilla::Relaxed> gSocketThread;
 
 #endif // !nsSocketTransportService_h__
diff --git a/netwerk/protocol/http/ConnectionDiagnostics.cpp b/netwerk/protocol/http/ConnectionDiagnostics.cpp
index a331e3dbfabd..5a3b818b23b5 100644
--- a/netwerk/protocol/http/ConnectionDiagnostics.cpp
+++ b/netwerk/protocol/http/ConnectionDiagnostics.cpp
@@ -15,8 +15,7 @@
 #include "nsIConsoleService.h"
 #include "nsHttpRequestHead.h"
 #include "nsServiceManagerUtils.h"
-
-extern PRThread *gSocketThread;
+#include "nsSocketTransportService2.h"
 
 namespace mozilla {
 namespace net {
diff --git a/netwerk/protocol/http/Http2Compression.cpp b/netwerk/protocol/http/Http2Compression.cpp
index d718cb4a4b4f..8fc30393de63 100644
--- a/netwerk/protocol/http/Http2Compression.cpp
+++ b/netwerk/protocol/http/Http2Compression.cpp
@@ -18,8 +18,6 @@
 #include "Http2HuffmanOutgoing.h"
 #include "mozilla/StaticPtr.h"
 
-extern PRThread *gSocketThread;
-
 namespace mozilla {
 namespace net {
 
diff --git a/netwerk/protocol/http/Http2Session.cpp b/netwerk/protocol/http/Http2Session.cpp
index 18ac243bade8..b87cd5b2a8fc 100644
--- a/netwerk/protocol/http/Http2Session.cpp
+++ b/netwerk/protocol/http/Http2Session.cpp
@@ -35,11 +35,7 @@
 #include "prnetdb.h"
 #include "sslt.h"
 #include "mozilla/Snprintf.h"
-
-#ifdef DEBUG
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
-#endif
+#include "nsSocketTransportService2.h"
 
 namespace mozilla {
 namespace net {
diff --git a/netwerk/protocol/http/Http2Stream.cpp b/netwerk/protocol/http/Http2Stream.cpp
index cbfe0715ee86..437cccbce413 100644
--- a/netwerk/protocol/http/Http2Stream.cpp
+++ b/netwerk/protocol/http/Http2Stream.cpp
@@ -32,11 +32,6 @@
 #include "nsStandardURL.h"
 #include "prnetdb.h"
 
-#ifdef DEBUG
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
-#endif
-
 namespace mozilla {
 namespace net {
 
diff --git a/netwerk/protocol/http/SpdySession31.cpp b/netwerk/protocol/http/SpdySession31.cpp
index f83884e0be6f..1c8209162f00 100644
--- a/netwerk/protocol/http/SpdySession31.cpp
+++ b/netwerk/protocol/http/SpdySession31.cpp
@@ -26,14 +26,10 @@
 #include "SpdySession31.h"
 #include "SpdyStream31.h"
 #include "SpdyZlibReporter.h"
+#include "nsSocketTransportService2.h"
 
 #include <algorithm>
 
-#ifdef DEBUG
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
-#endif
-
 namespace mozilla {
 namespace net {
 
diff --git a/netwerk/protocol/http/SpdyStream31.cpp b/netwerk/protocol/http/SpdyStream31.cpp
index 24138161e98a..c3cee26bc22d 100644
--- a/netwerk/protocol/http/SpdyStream31.cpp
+++ b/netwerk/protocol/http/SpdyStream31.cpp
@@ -28,11 +28,6 @@
 
 #include <algorithm>
 
-#ifdef DEBUG
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
-#endif
-
 namespace mozilla {
 namespace net {
 
diff --git a/netwerk/protocol/http/TunnelUtils.cpp b/netwerk/protocol/http/TunnelUtils.cpp
index 7252b2d6b593..31f578cc13f8 100644
--- a/netwerk/protocol/http/TunnelUtils.cpp
+++ b/netwerk/protocol/http/TunnelUtils.cpp
@@ -24,11 +24,6 @@
 #include "nsServiceManagerUtils.h"
 #include "nsComponentManagerUtils.h"
 
-#ifdef DEBUG
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
-#endif
-
 namespace mozilla {
 namespace net {
 
diff --git a/netwerk/protocol/http/nsHttpConnection.cpp b/netwerk/protocol/http/nsHttpConnection.cpp
index cca671699d67..dcb877ee949a 100644
--- a/netwerk/protocol/http/nsHttpConnection.cpp
+++ b/netwerk/protocol/http/nsHttpConnection.cpp
@@ -33,11 +33,6 @@
 #include "sslt.h"
 #include "TunnelUtils.h"
 
-#ifdef DEBUG
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
-#endif
-
 namespace mozilla {
 namespace net {
 
diff --git a/netwerk/protocol/http/nsHttpConnectionMgr.cpp b/netwerk/protocol/http/nsHttpConnectionMgr.cpp
index 8dd6cf599e2b..fccc97285915 100644
--- a/netwerk/protocol/http/nsHttpConnectionMgr.cpp
+++ b/netwerk/protocol/http/nsHttpConnectionMgr.cpp
@@ -37,9 +37,6 @@
 
 #include "mozilla/Telemetry.h"
 
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
-
 namespace mozilla {
 namespace net {
 
diff --git a/netwerk/protocol/http/nsHttpHandler.cpp b/netwerk/protocol/http/nsHttpHandler.cpp
index 8214d39c0d38..f34cb791620d 100644
--- a/netwerk/protocol/http/nsHttpHandler.cpp
+++ b/netwerk/protocol/http/nsHttpHandler.cpp
@@ -51,6 +51,7 @@
 #include "nsHttpChannelAuthProvider.h"
 #include "nsServiceManagerUtils.h"
 #include "nsComponentManagerUtils.h"
+#include "nsSocketTransportService2.h"
 
 #include "mozilla/net/NeckoChild.h"
 #include "mozilla/ipc/URIUtils.h"
@@ -73,11 +74,6 @@
 #include "mozilla/net/HttpChannelChild.h"
 
 
-#ifdef DEBUG
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
-#endif
-
 #define UA_PREF_PREFIX          "general.useragent."
 #ifdef XP_WIN
 #define UA_SPARE_PLATFORM
diff --git a/netwerk/protocol/http/nsHttpPipeline.cpp b/netwerk/protocol/http/nsHttpPipeline.cpp
index d21c424e2118..c21a018129b6 100644
--- a/netwerk/protocol/http/nsHttpPipeline.cpp
+++ b/netwerk/protocol/http/nsHttpPipeline.cpp
@@ -12,12 +12,11 @@
 #include "nsISocketTransport.h"
 #include "nsIPipe.h"
 #include "nsCOMPtr.h"
+#include "nsSocketTransportService2.h"
 #include <algorithm>
 
 #ifdef DEBUG
 #include "prthread.h"
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
 #endif
 
 namespace mozilla {
diff --git a/netwerk/protocol/http/nsHttpTransaction.cpp b/netwerk/protocol/http/nsHttpTransaction.cpp
index 94549231f3bc..ec5aaaa34e30 100644
--- a/netwerk/protocol/http/nsHttpTransaction.cpp
+++ b/netwerk/protocol/http/nsHttpTransaction.cpp
@@ -44,13 +44,6 @@
 
 //-----------------------------------------------------------------------------
 
-#ifdef DEBUG
-// defined by the socket transport service while active
-extern PRThread *gSocketThread;
-#endif
-
-//-----------------------------------------------------------------------------
-
 static NS_DEFINE_CID(kMultiplexInputStream, NS_MULTIPLEXINPUTSTREAM_CID);
 
 // Place a limit on how much non-compliant HTTP can be skipped while
diff --git a/netwerk/protocol/websocket/WebSocketChannel.cpp b/netwerk/protocol/websocket/WebSocketChannel.cpp
index ca850695d8af..5c1e6125ef8b 100644
--- a/netwerk/protocol/websocket/WebSocketChannel.cpp
+++ b/netwerk/protocol/websocket/WebSocketChannel.cpp
@@ -55,6 +55,7 @@
 #include "mozilla/StaticMutex.h"
 #include "mozilla/Telemetry.h"
 #include "mozilla/TimeStamp.h"
+#include "nsSocketTransportService2.h"
 
 #include "plbase64.h"
 #include "prmem.h"
@@ -70,8 +71,6 @@
 // dupe one constant we need from it
 #define CLOSE_GOING_AWAY 1001
 
-extern PRThread *gSocketThread;
-
 using namespace mozilla;
 using namespace mozilla::net;
 
diff --git a/netwerk/protocol/websocket/WebSocketEventService.cpp b/netwerk/protocol/websocket/WebSocketEventService.cpp
index 06984e75ef32..3855cc7f735f 100644
--- a/netwerk/protocol/websocket/WebSocketEventService.cpp
+++ b/netwerk/protocol/websocket/WebSocketEventService.cpp
@@ -12,8 +12,7 @@
 #include "mozilla/StaticPtr.h"
 #include "nsISupportsPrimitives.h"
 #include "nsXULAppAPI.h"
-
-extern PRThread *gSocketThread;
+#include "nsSocketTransportService2.h"
 
 namespace mozilla {
 namespace net {
diff --git a/netwerk/protocol/websocket/WebSocketFrame.cpp b/netwerk/protocol/websocket/WebSocketFrame.cpp
index 209942dc56a7..c8ce329f112f 100644
--- a/netwerk/protocol/websocket/WebSocketFrame.cpp
+++ b/netwerk/protocol/websocket/WebSocketFrame.cpp
@@ -7,8 +7,7 @@
 #include "WebSocketFrame.h"
 
 #include "WebSocketChannel.h"
-
-extern PRThread *gSocketThread;
+#include "nsSocketTransportService2.h"
 
 namespace mozilla {
 namespace net {