diff --git a/src/context.c b/src/context.c
index b4675267..234465cb 100644
--- a/src/context.c
+++ b/src/context.c
@@ -619,8 +619,9 @@ GLFWAPI void glfwMakeContextCurrent(GLFWwindow* handle)
 
     _GLFWwindow* window = (_GLFWwindow*) handle;
     _GLFWwindow* previous;
+    _GLFWusercontext* previousUserContext;
 
-    _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
+    previousUserContext = _glfwPlatformGetTls(&_glfw.usercontextSlot);
     previous = _glfwPlatformGetTls(&_glfw.contextSlot);
 
     if (window && window->context.client == GLFW_NO_API)
@@ -630,6 +631,12 @@ GLFWAPI void glfwMakeContextCurrent(GLFWwindow* handle)
         return;
     }
 
+    if (previousUserContext)
+    {
+        assert(previous==NULL);
+        previousUserContext->makeCurrent(NULL);
+    }
+
     if (previous)
     {
         if (!window || window->context.source != previous->context.source)
diff --git a/src/egl_context.c b/src/egl_context.c
index a82c3271..36aee66e 100644
--- a/src/egl_context.c
+++ b/src/egl_context.c
@@ -919,16 +919,32 @@ GLFWbool _glfwChooseVisualEGL(const _GLFWwndconfig* wndconfig,
 
 static void _glfwMakeUserContextCurrentEGL(_GLFWusercontext* context)
 {
-    if (!eglMakeCurrent(_glfw.egl.display,
-                        context->egl.surface,
-                        context->egl.surface,
-                        context->egl.handle))
+    if (context)
     {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
-                        "EGL: Failed to make user context current: %s",
-                        getEGLErrorString(eglGetError()));
-        _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
-        return;
+        if (!eglMakeCurrent(_glfw.egl.display,
+                            context->egl.surface,
+                            context->egl.surface,
+                            context->egl.handle))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "EGL: Failed to make user context current: %s",
+                            getEGLErrorString(eglGetError()));
+            _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
+            return;
+        }
+    }
+    else
+    {
+        if (!eglMakeCurrent(_glfw.egl.display,
+                            EGL_NO_SURFACE,
+                            EGL_NO_SURFACE,
+                            EGL_NO_CONTEXT))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "EGL: Failed to clear current user context: %s",
+                            getEGLErrorString(eglGetError()));
+            return;
+        }
     }
     _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
 }
diff --git a/src/glx_context.c b/src/glx_context.c
index e70ebfcc..ec8a033a 100644
--- a/src/glx_context.c
+++ b/src/glx_context.c
@@ -687,12 +687,24 @@ GLFWbool _glfwChooseVisualGLX(const _GLFWwndconfig* wndconfig,
 
 static void _glfwMakeUserContextCurrentGLX(_GLFWusercontext* context)
 {
-    if(!glXMakeCurrent(_glfw.x11.display, context->window->context.glx.window,context->glx.handle))
+	if (context)
+	{
+		if(!glXMakeCurrent(_glfw.x11.display, context->window->context.glx.window,context->glx.handle))
+		{
+			_glfwInputError(GLFW_PLATFORM_ERROR,
+							"GLX: Failed to make user context current");
+			_glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
+			return;
+		}
+	}
+	else
     {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
-                        "GLX: Failed to make user context current");
-        _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
-        return;
+        if (!glXMakeCurrent(_glfw.x11.display, None, NULL))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "GLX: Failed to clear current user context");
+            return;
+        }
     }
     _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
 }
diff --git a/src/nsgl_context.m b/src/nsgl_context.m
index 74fbbcd9..dc68d96a 100644
--- a/src/nsgl_context.m
+++ b/src/nsgl_context.m
@@ -357,9 +357,12 @@ static void _glfwMakeUserContextCurrentNSGL(_GLFWusercontext* context)
 {
     @autoreleasepool {
 
+    if (context)
         [context->nsgl.object makeCurrentContext];
+    else
+        [NSOpenGLContext clearCurrentContext];
 
-        _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
+    _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
 
     } // autoreleasepool
 }
@@ -368,7 +371,7 @@ static void _glfwDestroyUserContextNSGL(_GLFWusercontext* context)
 {
     @autoreleasepool {
 
-        [context->nsgl.object release];
+    [context->nsgl.object release];
 
     } // autoreleasepool
     free(context);
diff --git a/src/osmesa_context.c b/src/osmesa_context.c
index fcd978c5..f482d0fd 100644
--- a/src/osmesa_context.c
+++ b/src/osmesa_context.c
@@ -300,15 +300,18 @@ GLFWbool _glfwCreateContextOSMesa(_GLFWwindow* window,
 
 static void _glfwMakeUserContextCurrentOSMesa(_GLFWusercontext* context)
 {
-    if (!OSMesaMakeCurrent(context->osmesa.handle,
-                            context->window->context.osmesa.buffer,
-                            GL_UNSIGNED_BYTE,
-                            context->window->context.osmesa.width, context->window->context.osmesa.height))
+    if (context)
     {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
-                        "OSMesa: Failed to make user context current");
-        _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
-        return;
+        if (!OSMesaMakeCurrent(context->osmesa.handle,
+                                context->window->context.osmesa.buffer,
+                                GL_UNSIGNED_BYTE,
+                                context->window->context.osmesa.width, context->window->context.osmesa.height))
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "OSMesa: Failed to make user context current");
+            _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
+            return;
+        }
     }
     _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
 }
diff --git a/src/wgl_context.c b/src/wgl_context.c
index de2ca0a5..057c6f5a 100644
--- a/src/wgl_context.c
+++ b/src/wgl_context.c
@@ -787,13 +787,25 @@ GLFWbool _glfwCreateContextWGL(_GLFWwindow* window,
 
 static void _glfwMakeUserContextCurrentWGL(_GLFWusercontext* context)
 {
-    if(!wglMakeCurrent(context->window->context.wgl.dc,context->wgl.handle))
+    if (context)
     {
-        _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
-                             "WGL: Failed to make user context current");
-        _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
-        return;
+        if (!wglMakeCurrent(context->window->context.wgl.dc,context->wgl.handle))
+        {
+            _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
+                                 "WGL: Failed to make user context current");
+            _glfwPlatformSetTls(&_glfw.usercontextSlot, NULL);
+            return;
+        }
     }
+    else
+    {
+        if (!wglMakeCurrent(NULL, NULL))
+        {
+            _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
+                                 "WGL: Failed to clear current user context");
+        }
+    }
+
     _glfwPlatformSetTls(&_glfw.usercontextSlot, context);
 }