--- a/security/sandbox/linux/Sandbox.cpp
+++ b/security/sandbox/linux/Sandbox.cpp
@@ -475,16 +475,26 @@ static const Array<const char*, 1> kLibs
 #endif // NIGHTLY_BUILD
 
 void
 SandboxEarlyInit() {
   if (PR_GetEnv("MOZ_SANDBOXED") == nullptr) {
     return;
   }
 
+  // Fix LD_PRELOAD for any child processes.  See bug 1434392 comment #10;
+  // this can probably go away when audio remoting is mandatory.
+  const char* oldPreload = PR_GetEnv("MOZ_ORIG_LD_PRELOAD");
+  char* preloadEntry;
+  // This string is "leaked" because the environment takes ownership.
+  if (asprintf(&preloadEntry, "LD_PRELOAD=%s",
+               oldPreload ? oldPreload : "") != -1) {
+    PR_SetEnv(preloadEntry);
+  }
+
   // If TSYNC is not supported, set up signal handler
   // used to enable seccomp on each thread.
   if (!SandboxInfo::Get().Test(SandboxInfo::kHasSeccompTSync)) {
     // The signal number has to be chosen early, so that the
     // interceptions in SandboxHooks.cpp can prevent it from being
     // masked.
     const int tsyncSignum = FindFreeSignalNumber();
     if (tsyncSignum == 0) {

--- a/security/sandbox/linux/launch/SandboxLaunch.cpp
+++ b/security/sandbox/linux/launch/SandboxLaunch.cpp
@@ -152,16 +152,17 @@ PreloadSandboxLib(base::environment_map*
   nsAutoCString preload;
   // Prepend this, because people can and do preload libpthread.
   // (See bug 1222500.)
   preload.AssignLiteral("libmozsandbox.so");
   if (const char* oldPreload = PR_GetEnv("LD_PRELOAD")) {
     // Doesn't matter if oldPreload is ""; extra separators are ignored.
     preload.Append(' ');
     preload.Append(oldPreload);
+    (*aEnv)["MOZ_ORIG_LD_PRELOAD"] = oldPreload;
   }
   MOZ_ASSERT(aEnv->count("LD_PRELOAD") == 0);
   (*aEnv)["LD_PRELOAD"] = preload.get();
 }
 
 static void
 AttachSandboxReporter(base::file_handle_mapping_vector* aFdMap)
 {