SFML Xlib thread-safety

diff --git a/src/SFML/Window/Linux/Display.cpp b/src/SFML/Window/Linux/Display.cpp
index 2420268..f46e525 100644
--- a/src/SFML/Window/Linux/Display.cpp
+++ b/src/SFML/Window/Linux/Display.cpp
@@ -26,6 +26,7 @@
 // Headers
 ////////////////////////////////////////////////////////////
 #include <SFML/Window/Linux/Display.hpp>
+#include <X11/Xlib.h>
 #include <cassert>


@@ -43,6 +44,9 @@ namespace priv
 ////////////////////////////////////////////////////////////
 Display* OpenDisplay()
 {
+    // Ensure thread-safety
+    XInitThreads();
+
     if (referenceCount == 0)
         sharedDisplay = XOpenDisplay(NULL);
     referenceCount++;
diff --git a/src/SFML/Window/Linux/VideoModeImpl.cpp b/src/SFML/Window/Linux/VideoModeImpl.cpp
index 0b8aca8..8c439f0 100644
--- a/src/SFML/Window/Linux/VideoModeImpl.cpp
+++ b/src/SFML/Window/Linux/VideoModeImpl.cpp
@@ -42,6 +42,9 @@ std::vector<VideoMode> VideoModeImpl::getFullscreenModes()
 {
     std::vector<VideoMode> modes;

+    // Ensure thread-safety
+    XInitThreads();
+
     // Open a connection with the X server
     Display* display = OpenDisplay();
     if (display)
@@ -119,6 +122,9 @@ VideoMode VideoModeImpl::getDesktopMode()
 {
     VideoMode desktopMode;

+    // Ensure thread-safety
+    XInitThreads();
+
     // Open a connection with the X server
     Display* display = OpenDisplay();
     if (display)
diff --git a/src/SFML/Window/Linux/WindowImplX11.cpp b/src/SFML/Window/Linux/WindowImplX11.cpp
index 3cf2293..b38e6e6 100644
--- a/src/SFML/Window/Linux/WindowImplX11.cpp
+++ b/src/SFML/Window/Linux/WindowImplX11.cpp
@@ -30,6 +30,7 @@
 #include <SFML/Window/Linux/Display.hpp>
 #include <SFML/System/Utf.hpp>
 #include <SFML/System/Err.hpp>
+#include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/keysym.h>
 #include <X11/extensions/Xrandr.h>
@@ -72,6 +73,9 @@ m_oldVideoMode(-1),
 m_hiddenCursor(0),
 m_keyRepeat   (true)
 {
+    // Ensure thread-safety
+    XInitThreads();
+
     // Open a connection with the X server
     m_display = OpenDisplay();
     m_screen  = DefaultScreen(m_display);
@@ -101,6 +105,9 @@ m_oldVideoMode(-1),
 m_hiddenCursor(0),
 m_keyRepeat   (true)
 {
+    // Ensure thread-safety
+    XInitThreads();
+
     // Open a connection with the X server
     m_display = OpenDisplay();
     m_screen  = DefaultScreen(m_display);