diff --git a/README.md b/README.md
index 43ad0575..41f776c8 100644
--- a/README.md
+++ b/README.md
@@ -76,6 +76,7 @@ GLFW bundles a number of dependencies in the `deps/` directory.
  - [X11] Bugfix: The response to `_NET_WM_PING` was sent to the wrong window
  - [X11] Bugfix: Character input via XIM did not work in many cases
  - [X11] Bugfix: No fallback existed for missing `_NET_ACTIVE_WINDOW` support
+ - [X11] Bugfix: Some significant window focus events were ignored
  - [WGL] Removed `GLFW_USE_DWM_SWAP_INTERVAL` compile-time option
  - [WGL] Bugfix: Swap interval was ignored when DWM was enabled
  - [GLX] Added dependency on `libdl` on systems where it provides `dlopen`
diff --git a/src/x11_window.c b/src/x11_window.c
index 48f25011..def84616 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -1220,33 +1220,43 @@ static void processEvent(XEvent *event)
 
         case FocusIn:
         {
-            if (event->xfocus.mode == NotifyNormal)
+            if (event->xfocus.mode == NotifyGrab ||
+                event->xfocus.mode == NotifyUngrab)
             {
-                if (window->x11.ic)
-                    XSetICFocus(window->x11.ic);
-
-                _glfwInputWindowFocus(window, GL_TRUE);
-
-                if (window->cursorMode == GLFW_CURSOR_DISABLED)
-                    disableCursor(window);
+                // Ignore focus events from popup indicator windows, window menu
+                // key chords and window dragging
+                return;
             }
 
+            if (window->x11.ic)
+                XSetICFocus(window->x11.ic);
+
+            _glfwInputWindowFocus(window, GL_TRUE);
+
+            if (window->cursorMode == GLFW_CURSOR_DISABLED)
+                disableCursor(window);
+
             return;
         }
 
         case FocusOut:
         {
-            if (event->xfocus.mode == NotifyNormal)
+            if (event->xfocus.mode == NotifyGrab ||
+                event->xfocus.mode == NotifyUngrab)
             {
-                if (window->x11.ic)
-                    XUnsetICFocus(window->x11.ic);
-
-                _glfwInputWindowFocus(window, GL_FALSE);
-
-                if (window->cursorMode == GLFW_CURSOR_DISABLED)
-                    restoreCursor(window);
+                // Ignore focus events from popup indicator windows, window menu
+                // key chords and window dragging
+                return;
             }
 
+            if (window->x11.ic)
+                XUnsetICFocus(window->x11.ic);
+
+            _glfwInputWindowFocus(window, GL_FALSE);
+
+            if (window->cursorMode == GLFW_CURSOR_DISABLED)
+                restoreCursor(window);
+
             return;
         }