diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5256e086..09dd0fd5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -130,37 +130,38 @@ if (_GLFW_X11)
     list(APPEND glfw_INCLUDE_DIRS ${X11_X11_INCLUDE_PATH})
     list(APPEND glfw_LIBRARIES ${X11_X11_LIB})
 
-    # Check for XRandR (modern resolution switching extension)
-    if (X11_Xrandr_FOUND)
-        set(_GLFW_HAS_XRANDR 1) 
-        list(APPEND glfw_INCLUDE_DIRS ${X11_Xrandr_INCLUDE_PATH})
-        list(APPEND glfw_LIBRARIES ${X11_Xrandr_LIB})
-        set(GLFW_PKG_DEPS "${GLFW_PKG_DEPS} xrandr")
+    # Check for XRandR (modern resolution switching and gamma control)
+    if (NOT X11_Xrandr_FOUND)
+        message(FATAL_ERROR "The RandR extension was not found")
     endif()
 
-    # Check for Xf86VidMode (fallback legacy resolution switching extension)
-    if (X11_xf86vmode_FOUND)
-        set(_GLFW_HAS_XF86VIDMODE 1)
-        list(APPEND glfw_INCLUDE_DIRS ${X11_xf86vmode_INCLUDE_PATH})
-    
-        # NOTE: This is a workaround for CMake bug 0006976 (missing
-        # X11_xf86vmode_LIB variable)
-        if (X11_xf86vmode_LIB)
-            list(APPEND glfw_LIBRARIES ${X11_xf86vmode_LIB})
-        else()
-            list(APPEND glfw_LIBRARIES Xxf86vm)
-        endif()
+    list(APPEND glfw_INCLUDE_DIRS ${X11_Xrandr_INCLUDE_PATH})
+    list(APPEND glfw_LIBRARIES ${X11_Xrandr_LIB})
+    set(GLFW_PKG_DEPS "${GLFW_PKG_DEPS} xrandr")
 
-        set(GLFW_PKG_DEPS "${GLFW_PKG_DEPS} xxf86vm")
-    endif() 
+    # Check for Xf86VidMode (fallback gamma control)
+    if (NOT X11_xf86vmode_FOUND)
+        message(FATAL_ERROR "The Xf86VidMode extension was not found")
+    endif()
+
+    list(APPEND glfw_INCLUDE_DIRS ${X11_xf86vmode_INCLUDE_PATH})
+    set(GLFW_PKG_DEPS "${GLFW_PKG_DEPS} xxf86vm")
+
+    # NOTE: This is a workaround for CMake bug 0006976 (missing
+    # X11_xf86vmode_LIB variable)
+    if (X11_xf86vmode_LIB)
+        list(APPEND glfw_LIBRARIES ${X11_xf86vmode_LIB})
+    else()
+        list(APPEND glfw_LIBRARIES Xxf86vm)
+    endif()
 
     # Check for Xkb (X keyboard extension)
-    if (X11_Xkb_FOUND)
-        list(APPEND glfw_INCLUDE_DIR ${X11_Xkb_INCLUDE_PATH})
-    else()
+    if (NOT X11_Xkb_FOUND)
         message(FATAL_ERROR "The X keyboard extension was not found")
     endif() 
 
+    list(APPEND glfw_INCLUDE_DIR ${X11_Xkb_INCLUDE_PATH})
+
     find_library(RT_LIBRARY rt)
     mark_as_advanced(RT_LIBRARY)
     if (RT_LIBRARY)
diff --git a/readme.html b/readme.html
index ab904d3e..7037378b 100644
--- a/readme.html
+++ b/readme.html
@@ -359,6 +359,7 @@ version of GLFW.</p>
   <li>[X11] Added the POSIX <code>CLOCK_MONOTONIC</code> time source as the preferred method</li>
   <li>[X11] Added dependency on libm, where present</li>
   <li>[X11] Added support for the <code>_NET_WM_NAME</code> and <code>_NET_WM_ICON_NAME</code> EWMH window properties</li>
+  <li>[X11] Made client-side RandR and Xf86VidMode extensions required</li>
   <li>[X11] Bugfix: Some window properties required by the ICCCM were not set</li>
   <li>[X11] Bugfix: Calling <code>glXCreateContextAttribsARB</code> with an unavailable OpenGL version caused the application to terminate with a <code>BadMatch</code> Xlib error</li>
   <li>[X11] Bugfix: A synchronization point necessary for jitter-free locked cursor mode was incorrectly removed</li>
diff --git a/src/config.h.in b/src/config.h.in
index ad681b98..b289520b 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -57,11 +57,6 @@
 // Define this to 1 to disable dynamic loading of winmm
 #cmakedefine _GLFW_NO_DLOAD_WINMM
 
-// Define this to 1 if XRandR is available
-#cmakedefine _GLFW_HAS_XRANDR
-// Define this to 1 if Xf86VidMode is available
-#cmakedefine _GLFW_HAS_XF86VIDMODE
-
 // Define this to 1 if glXGetProcAddress is available
 #cmakedefine _GLFW_HAS_GLXGETPROCADDRESS
 // Define this to 1 if glXGetProcAddressARB is available
diff --git a/src/x11_gamma.c b/src/x11_gamma.c
index 9856ace0..d3986f11 100644
--- a/src/x11_gamma.c
+++ b/src/x11_gamma.c
@@ -43,7 +43,6 @@
 
 void _glfwInitGammaRamp(void)
 {
-#ifdef _GLFW_HAS_XRANDR
     // RandR gamma support is only available with version 1.2 and above
     if (_glfw.x11.randr.available &&
         (_glfw.x11.randr.versionMajor > 1 ||
@@ -68,9 +67,7 @@ void _glfwInitGammaRamp(void)
 
         XRRFreeScreenResources(rr);
     }
-#endif /*_GLFW_HAS_XRANDR*/
 
-#if defined(_GLFW_HAS_XF86VIDMODE)
     if (_glfw.x11.vidmode.available && !_glfw.originalRampSize)
     {
         // Get the gamma size using XF86VidMode
@@ -78,7 +75,6 @@ void _glfwInitGammaRamp(void)
                                     _glfw.x11.screen,
                                     &_glfw.originalRampSize);
     }
-#endif /*_GLFW_HAS_XF86VIDMODE*/
 
     if (_glfw.originalRampSize)
     {
@@ -121,7 +117,6 @@ void _glfwPlatformGetGammaRamp(GLFWgammaramp* ramp)
 
     if (_glfw.x11.randr.available && !_glfw.x11.randr.gammaBroken)
     {
-#if defined (_GLFW_HAS_XRANDR)
         size_t size = GLFW_GAMMA_RAMP_SIZE * sizeof(unsigned short);
 
         XRRScreenResources* rr = XRRGetScreenResources(_glfw.x11.display,
@@ -138,18 +133,15 @@ void _glfwPlatformGetGammaRamp(GLFWgammaramp* ramp)
 
         XRRFreeGamma(gamma);
         XRRFreeScreenResources(rr);
-#endif /*_GLFW_HAS_XRANDR*/
     }
     else if (_glfw.x11.vidmode.available)
     {
-#if defined (_GLFW_HAS_XF86VIDMODE)
         XF86VidModeGetGammaRamp(_glfw.x11.display,
                                 _glfw.x11.screen,
                                 GLFW_GAMMA_RAMP_SIZE,
                                 ramp->red,
                                 ramp->green,
                                 ramp->blue);
-#endif /*_GLFW_HAS_XF86VIDMODE*/
     }
 }
 
@@ -171,7 +163,6 @@ void _glfwPlatformSetGammaRamp(const GLFWgammaramp* ramp)
 
     if (_glfw.x11.randr.available && !_glfw.x11.randr.gammaBroken)
     {
-#if defined (_GLFW_HAS_XRANDR)
         int i;
         size_t size = GLFW_GAMMA_RAMP_SIZE * sizeof(unsigned short);
 
@@ -192,18 +183,15 @@ void _glfwPlatformSetGammaRamp(const GLFWgammaramp* ramp)
         }
 
         XRRFreeScreenResources(rr);
-#endif /*_GLFW_HAS_XRANDR*/
     }
     else if (_glfw.x11.vidmode.available)
     {
-#if defined (_GLFW_HAS_XF86VIDMODE)
         XF86VidModeSetGammaRamp(_glfw.x11.display,
                                 _glfw.x11.screen,
                                 GLFW_GAMMA_RAMP_SIZE,
                                 (unsigned short*) ramp->red,
                                 (unsigned short*) ramp->green,
                                 (unsigned short*) ramp->blue);
-#endif /*_GLFW_HAS_XF86VIDMODE*/
     }
 }
 
diff --git a/src/x11_init.c b/src/x11_init.c
index ffcb7195..6e9761b5 100644
--- a/src/x11_init.c
+++ b/src/x11_init.c
@@ -483,17 +483,12 @@ static GLboolean initDisplay(void)
     _glfw.x11.root = RootWindow(_glfw.x11.display, _glfw.x11.screen);
 
     // Check for XF86VidMode extension
-#ifdef _GLFW_HAS_XF86VIDMODE
     _glfw.x11.vidmode.available =
         XF86VidModeQueryExtension(_glfw.x11.display,
                                   &_glfw.x11.vidmode.eventBase,
                                   &_glfw.x11.vidmode.errorBase);
-#else
-    _glfw.x11.vidmode.available = GL_FALSE;
-#endif /*_GLFW_HAS_XF86VIDMODE*/
 
     // Check for RandR extension
-#ifdef _GLFW_HAS_XRANDR
     _glfw.x11.randr.available =
         XRRQueryExtension(_glfw.x11.display,
                           &_glfw.x11.randr.eventBase,
@@ -517,9 +512,6 @@ static GLboolean initDisplay(void)
             _glfw.x11.randr.available = GL_FALSE;
         }
     }
-#else
-    _glfw.x11.randr.available = GL_FALSE;
-#endif /*_GLFW_HAS_XRANDR*/
 
     // Check if Xkb is supported on this display
     _glfw.x11.xkb.versionMajor = 1;
@@ -681,15 +673,6 @@ const char* _glfwPlatformGetVersionString(void)
 #elif defined(_GLFW_EGL)
         " EGL"
 #endif
-#if defined(_GLFW_HAS_XRANDR)
-        " XRandR"
-#endif
-#if defined(_GLFW_HAS_XF86VIDMODE)
-        " Xf86VidMode"
-#endif
-#if !defined(_GLFW_HAS_XRANDR) && !defined(_GLFW_HAS_XF86VIDMODE)
-        " no-mode-switching-support"
-#endif
 #if defined(_GLFW_HAS_GLXGETPROCADDRESS)
         " glXGetProcAddress"
 #elif defined(_GLFW_HAS_GLXGETPROCADDRESSARB)
diff --git a/src/x11_monitor.c b/src/x11_monitor.c
index 3cee50d6..cf8edb75 100644
--- a/src/x11_monitor.c
+++ b/src/x11_monitor.c
@@ -49,7 +49,6 @@ int _glfwGetClosestVideoMode(_GLFWmonitor* monitor, int* width, int* height)
 
     if (_glfw.x11.randr.available)
     {
-#if defined(_GLFW_HAS_XRANDR)
         int sizecount, bestsize;
         XRRScreenConfiguration* sc;
         XRRScreenSize* sizelist;
@@ -85,7 +84,6 @@ int _glfwGetClosestVideoMode(_GLFWmonitor* monitor, int* width, int* height)
 
         if (bestsize != -1)
             return bestsize;
-#endif /*_GLFW_HAS_XRANDR*/
     }
 
     // Default: Simply use the screen resolution
@@ -104,7 +102,6 @@ void _glfwSetVideoModeMODE(_GLFWmonitor* monitor, int mode)
 {
     if (_glfw.x11.randr.available)
     {
-#if defined(_GLFW_HAS_XRANDR)
         XRRScreenConfiguration* sc;
         Window root;
 
@@ -131,7 +128,6 @@ void _glfwSetVideoModeMODE(_GLFWmonitor* monitor, int mode)
                            CurrentTime);
 
         XRRFreeScreenConfigInfo(sc);
-#endif /*_GLFW_HAS_XRANDR*/
     }
 }
 
@@ -163,7 +159,6 @@ void _glfwRestoreVideoMode(_GLFWmonitor* monitor)
 
     if (_glfw.x11.randr.available)
     {
-#if defined(_GLFW_HAS_XRANDR)
         XRRScreenConfiguration* sc;
 
         sc = XRRGetScreenInfo(_glfw.x11.display, _glfw.x11.root);
@@ -176,7 +171,6 @@ void _glfwRestoreVideoMode(_GLFWmonitor* monitor)
                            CurrentTime);
 
         XRRFreeScreenConfigInfo(sc);
-#endif /*_GLFW_HAS_XRANDR*/
     }
 
     monitor->x11.modeChanged = GL_FALSE;
@@ -200,7 +194,6 @@ _GLFWmonitor** _glfwPlatformGetMonitors(int* found)
 
     if (_glfw.x11.randr.available)
     {
-#if defined (_GLFW_HAS_XRANDR)
         int i;
         RROutput primary;
         XRRScreenResources* sr;
@@ -249,7 +242,6 @@ _GLFWmonitor** _glfwPlatformGetMonitors(int* found)
             monitors[*found]->x11.output = oi;
             (*found)++;
         }
-#endif /*_GLFW_HAS_XRANDR*/
     }
     else
     {
@@ -284,11 +276,7 @@ _GLFWmonitor** _glfwPlatformGetMonitors(int* found)
 void _glfwPlatformDestroyMonitor(_GLFWmonitor* monitor)
 {
     if (_glfw.x11.randr.available)
-    {
-#if defined (_GLFW_HAS_XRANDR)
         XRRFreeOutputInfo(monitor->x11.output);
-#endif /*_GLFW_HAS_XRANDR*/
-    }
 }
 
 
@@ -310,7 +298,6 @@ GLFWvidmode* _glfwPlatformGetVideoModes(_GLFWmonitor* monitor, int* found)
 
     if (_glfw.x11.randr.available)
     {
-#if defined(_GLFW_HAS_XRANDR)
         XRRScreenResources* sr;
         int i, j, count = monitor->x11.output->nmode;
 
@@ -363,7 +350,6 @@ GLFWvidmode* _glfwPlatformGetVideoModes(_GLFWmonitor* monitor, int* found)
         }
 
         XRRFreeScreenResources(sr);
-#endif /*_GLFW_HAS_XRANDR*/
     }
     else
     {
@@ -395,7 +381,6 @@ void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode)
 {
     if (_glfw.x11.randr.available)
     {
-#if defined (_GLFW_HAS_XRANDR)
         XRRScreenResources* sr;
         XRRCrtcInfo* ci;
 
@@ -422,7 +407,6 @@ void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode)
 
         XRRFreeCrtcInfo(ci);
         XRRFreeScreenResources(sr);
-#endif /*_GLFW_HAS_XRANDR*/
     }
     else
     {
diff --git a/src/x11_platform.h b/src/x11_platform.h
index 50bf7b1d..6e660eb7 100644
--- a/src/x11_platform.h
+++ b/src/x11_platform.h
@@ -38,15 +38,11 @@
 #include <X11/keysym.h>
 #include <X11/Xatom.h>
 
-// With XFree86, we can use the XF86VidMode extension
-#if defined(_GLFW_HAS_XF86VIDMODE)
- #include <X11/extensions/xf86vmode.h>
-#endif
+// The Xf86VidMode extension provides fallback gamma control
+#include <X11/extensions/xf86vmode.h>
 
 // The XRandR extension provides mode setting and gamma control
-#if defined(_GLFW_HAS_XRANDR)
- #include <X11/extensions/Xrandr.h>
-#endif
+#include <X11/extensions/Xrandr.h>
 
 // The Xkb extension provides improved keyboard support
 #include <X11/XKBlib.h>
@@ -207,13 +203,11 @@ typedef struct _GLFWmonitorX11
 {
     GLboolean       modeChanged;
 
-#if defined(_GLFW_HAS_XRANDR)
     XRROutputInfo*  output;
     SizeID          oldSizeID;
     int             oldWidth;
     int             oldHeight;
     Rotation        oldRotation;
-#endif /*_GLFW_HAS_XRANDR*/
 
 } _GLFWmonitorX11;
 
diff --git a/src/x11_window.c b/src/x11_window.c
index 7fb7747a..f396b252 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -816,7 +816,6 @@ static void processEvent(XEvent *event)
 
         default:
         {
-#if defined(_GLFW_HAS_XRANDR)
             switch (event->type - _glfw.x11.randr.eventBase)
             {
                 case RRScreenChangeNotify:
@@ -826,7 +825,7 @@ static void processEvent(XEvent *event)
                     break;
                 }
             }
-#endif /*_GLFW_HAS_XRANDR*/
+
             break;
         }
     }