diff --git a/dom/plugins/PluginModuleChild.cpp b/dom/plugins/PluginModuleChild.cpp
index b09a74f21dc8..2572ccde1383 100644
--- a/dom/plugins/PluginModuleChild.cpp
+++ b/dom/plugins/PluginModuleChild.cpp
@@ -285,7 +285,7 @@ PluginModuleChild::ActorDestroy(ActorDestroyReason why)
 
 
 #ifdef OS_LINUX
-    printf("TEST-UNEXPECTED-FAIL | plugin process %d | initiating shutdown\n", getpid());
+    fprintf(stderr, "TEST-UNEXPECTED-FAIL | plugin process %d | initiating shutdown\n", getpid());
 #endif
 
 
diff --git a/ipc/chromium/src/base/process_util_linux.cc b/ipc/chromium/src/base/process_util_linux.cc
index 83fc9836056e..4b17ab858124 100644
--- a/ipc/chromium/src/base/process_util_linux.cc
+++ b/ipc/chromium/src/base/process_util_linux.cc
@@ -64,7 +64,7 @@ bool LaunchApp(const std::vector<std::string>& argv,
   } else {
 
 
-      printf("TEST-UNEXPECTED-FAIL | ==> process %d launched | child process %d\n", GetCurrentProcId(), pid);
+      fprintf(stderr, "TEST-UNEXPECTED-FAIL | ==> process %d launched | child process %d\n", GetCurrentProcId(), pid);
 
 
 
diff --git a/ipc/chromium/src/chrome/common/process_watcher_posix_sigchld.cc b/ipc/chromium/src/chrome/common/process_watcher_posix_sigchld.cc
index dec42a32ac9e..1f102aeabb39 100644
--- a/ipc/chromium/src/chrome/common/process_watcher_posix_sigchld.cc
+++ b/ipc/chromium/src/chrome/common/process_watcher_posix_sigchld.cc
@@ -198,7 +198,7 @@ public:
 
 
 
-      printf("TEST-UNEXPECTED-FAIL | process %d reaped | child process (got SIGCHLD, exited normally)\n", getpid());
+      fprintf(stderr, "TEST-UNEXPECTED-FAIL | process %d reaped | child process (got SIGCHLD, exited normally)\n", getpid());
 
 
 
@@ -217,7 +217,7 @@ public:
 
 
 
-    printf("TEST-UNEXPECTED-FAIL | process %d reaped | child process (waitpid() on shutdown)\n", getpid());
+    fprintf(stderr, "TEST-UNEXPECTED-FAIL | process %d reaped | child process (waitpid() on shutdown)\n", getpid());
 
 
 
@@ -264,7 +264,7 @@ ProcessWatcher::EnsureProcessTerminated(base::ProcessHandle process,
 
 
 
-    printf("TEST-UNEXPECTED-FAIL | process %d reaped | child process %d (it was already dead)\n", getpid(), process);
+    fprintf(stderr, "TEST-UNEXPECTED-FAIL | process %d reaped | child process %d (it was already dead)\n", getpid(), process);
 
 
 
diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
index 99d0f6f434c1..944a6b5066ac 100644
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -3598,7 +3598,7 @@ XRE_main(int argc, char* argv[], const nsXREAppData* aAppData)
 
 
 #ifdef OS_LINUX
-  printf("TEST-UNEXPECTED-FAIL | browser process %d | exiting\n", getpid());
+  fprintf(stderr, "TEST-UNEXPECTED-FAIL | browser process %d | exiting\n", getpid());
 #endif
 
 
diff --git a/toolkit/xre/nsEmbedFunctions.cpp b/toolkit/xre/nsEmbedFunctions.cpp
index 7e4eed8e1df5..2997ee3296ef 100644
--- a/toolkit/xre/nsEmbedFunctions.cpp
+++ b/toolkit/xre/nsEmbedFunctions.cpp
@@ -373,7 +373,7 @@ XRE_InitChildProcess(int aArgc,
 
 
 #ifdef OS_LINUX
-  printf("TEST-UNEXPECTED-FAIL | plugin process %d | IO thread joined XPCOM thread, exiting\n", getpid());
+  fprintf(stderr, "TEST-UNEXPECTED-FAIL | plugin process %d | IO thread joined XPCOM thread, exiting\n", getpid());
 #endif
 
 
@@ -514,7 +514,7 @@ XRE_ShutdownChildProcess()
 
 
 #ifdef OS_LINUX
-    printf("TEST-UNEXPECTED-FAIL | plugin process %d | posted quit task to IO thread\n", getpid());
+    fprintf(stderr, "TEST-UNEXPECTED-FAIL | plugin process %d | posted quit task to IO thread\n", getpid());
 #endif