diff --git a/src/Base/Console.cpp b/src/Base/Console.cpp
index 97d371e73..084f477ca 100644
--- a/src/Base/Console.cpp
+++ b/src/Base/Console.cpp
@@ -42,9 +42,6 @@ using namespace Base;
 
 
 
-char format[4024];  // global buffer 
-const unsigned int format_len = 4024;
-
 
 //**************************************************************************
 // Construction destruction
@@ -171,6 +168,9 @@ bool ConsoleSingleton::IsMsgTypeEnabled(const char* sObs, FreeCAD_ConsoleMsgType
  */
 void ConsoleSingleton::Message( const char *pMsg, ... )
 {
+    char format[4024];
+    const unsigned int format_len = 4024;
+
     va_list namelessVars;
     va_start(namelessVars, pMsg);  // Get the "..." vars
     vsnprintf(format, format_len, pMsg, namelessVars);
@@ -195,6 +195,9 @@ void ConsoleSingleton::Message( const char *pMsg, ... )
  */
 void ConsoleSingleton::Warning( const char *pMsg, ... )
 {
+    char format[4024];
+    const unsigned int format_len = 4024;
+
     va_list namelessVars;
     va_start(namelessVars, pMsg);  // Get the "..." vars
     vsnprintf(format, format_len, pMsg, namelessVars);
@@ -219,6 +222,9 @@ void ConsoleSingleton::Warning( const char *pMsg, ... )
  */
 void ConsoleSingleton::Error( const char *pMsg, ... )
 {
+    char format[4024];
+    const unsigned int format_len = 4024;
+
     va_list namelessVars;
     va_start(namelessVars, pMsg);  // Get the "..." vars
     vsnprintf(format, format_len, pMsg, namelessVars);
@@ -246,6 +252,9 @@ void ConsoleSingleton::Error( const char *pMsg, ... )
 
 void ConsoleSingleton::Log( const char *pMsg, ... )
 {
+    char format[4024];
+    const unsigned int format_len = 4024;
+
     if (!_bVerbose)
     {
         va_list namelessVars;
diff --git a/src/Gui/CommandTest.cpp b/src/Gui/CommandTest.cpp
index 32f3a0c8b..245c0d6be 100644
--- a/src/Gui/CommandTest.cpp
+++ b/src/Gui/CommandTest.cpp
@@ -33,6 +33,8 @@
 # include <QMdiSubWindow>
 # include <QWaitCondition>
 # include <QTranslator>
+# include <QRunnable>
+# include <QThreadPool>
 #endif
 
 #include <Base/Console.h>
@@ -638,6 +640,110 @@ bool CmdTestMDI3::isActive(void)
     return getMainWindow()->activeWindow();
 }
 
+DEF_STD_CMD(CmdTestConsoleOutput);
+
+CmdTestConsoleOutput::CmdTestConsoleOutput()
+  : Command("Std_TestConsoleOutput")
+{
+    sGroup      = QT_TR_NOOP("Standard-Test");
+    sMenuText   = QT_TR_NOOP("Test console output");
+    sToolTipText= QT_TR_NOOP("Test console output");
+    sStatusTip  = QT_TR_NOOP("Test console output");
+}
+
+namespace Gui {
+class TestConsoleObserver : public Base::ConsoleObserver
+{
+    QMutex mutex;
+public:
+    int matchMsg, matchWrn, matchErr, matchLog;
+    TestConsoleObserver() : matchMsg(0), matchWrn(0), matchErr(0), matchLog(0)
+    {
+    }
+    virtual void Warning(const char * msg)
+    {
+        mutex.lock();
+        matchWrn += strcmp(msg, "Write a warning to the console output.\n");
+        mutex.unlock();
+    }
+    virtual void Message(const char * msg)
+    {
+        mutex.lock();
+        matchMsg += strcmp(msg, "Write a message to the console output.\n");
+        mutex.unlock();
+    }
+    virtual void Error(const char * msg)
+    {
+        mutex.lock();
+        matchErr += strcmp(msg, "Write an error to the console output.\n");
+        mutex.unlock();
+    }
+    virtual void Log(const char * msg)
+    {
+        mutex.lock();
+        matchLog += strcmp(msg, "Write a log to the console output.\n");
+        mutex.unlock();
+    }
+};
+
+class ConsoleMessageTask : public QRunnable
+{
+public:
+    void run()
+    {
+        for (int i=0; i<10; i++)
+            Base::Console().Message("Write a message to the console output.\n");
+    }
+};
+
+class ConsoleWarningTask : public QRunnable
+{
+public:
+    void run()
+    {
+        for (int i=0; i<10; i++)
+            Base::Console().Warning("Write a warning to the console output.\n");
+    }
+};
+
+class ConsoleErrorTask : public QRunnable
+{
+public:
+    void run()
+    {
+        for (int i=0; i<10; i++)
+            Base::Console().Error("Write an error to the console output.\n");
+    }
+};
+
+class ConsoleLogTask : public QRunnable
+{
+public:
+    void run()
+    {
+        for (int i=0; i<10; i++)
+            Base::Console().Log("Write a log to the console output.\n");
+    }
+};
+
+}
+
+void CmdTestConsoleOutput::activated(int iMsg)
+{
+    TestConsoleObserver obs;
+    Base::Console().AttachObserver(&obs);
+    QThreadPool::globalInstance()->start(new ConsoleMessageTask);
+    QThreadPool::globalInstance()->start(new ConsoleWarningTask);
+    QThreadPool::globalInstance()->start(new ConsoleErrorTask);
+    QThreadPool::globalInstance()->start(new ConsoleLogTask);
+    QThreadPool::globalInstance()->waitForDone();
+    Base::Console().DetachObserver(&obs);
+
+    if (obs.matchMsg > 0 || obs.matchWrn > 0 || obs.matchErr > 0 || obs.matchLog > 0) {
+        Base::Console().Error("Race condition in Console class\n");
+    }
+}
+
 
 namespace Gui {
 
@@ -661,6 +767,7 @@ void CreateTestCommands(void)
     rcCmdMgr.addCommand(new CmdTestMDI1());
     rcCmdMgr.addCommand(new CmdTestMDI2());
     rcCmdMgr.addCommand(new CmdTestMDI3());
+    rcCmdMgr.addCommand(new CmdTestConsoleOutput());
 }
 
 } // namespace Gui
diff --git a/src/Gui/Qt4All.h b/src/Gui/Qt4All.h
index 3db34caf9..dc2cf4349 100644
--- a/src/Gui/Qt4All.h
+++ b/src/Gui/Qt4All.h
@@ -37,12 +37,14 @@
 #include <QProcess>
 #include <qrect.h>
 #include <qregexp.h>
+#include <qrunnable.h>
 #include <QSet>
 #include <QSignalMapper>
 #include <QTemporaryFile>
 #include <qtextcodec.h>
 #include <qtextstream.h>
 #include <qthread.h>
+#include <qthreadpool.h>
 #include <qtimer.h>
 #include <qtranslator.h>
 #include <QUrl>
@@ -122,7 +124,7 @@
 #include <QStylePainter>
 #include <QSyntaxHighlighter>
 #include <qtabbar.h>
-#include <QTableView>
+#include <QTableView>
 #include <qtabwidget.h>
 #include <QTextBrowser>
 #include <QTextDocument>
diff --git a/src/Mod/Test/InitGui.py b/src/Mod/Test/InitGui.py
index 51a3281cb..f56a6ebba 100644
--- a/src/Mod/Test/InitGui.py
+++ b/src/Mod/Test/InitGui.py
@@ -86,6 +86,10 @@ class TestWorkbench ( Workbench ):
 		list = ["Std_TestProgress1", "Std_TestProgress2", "Std_TestProgress3", "Std_TestProgress4", "Std_TestProgress5"]
 		self.appendMenu(menu,list)
 
+		menu = ["Test &Commands","Console"]
+		list = ["Std_TestConsoleOutput"]
+		self.appendMenu(menu,list)
+
 		menu = ["Test &Commands","MDI"]
 		list = ["Std_MDITest1", "Std_MDITest2", "Std_MDITest3"]
 		self.appendMenu(menu,list)