diff --git a/README.md b/README.md
index 64416958..e6440d51 100644
--- a/README.md
+++ b/README.md
@@ -190,6 +190,8 @@ information on what to include when reporting a bug.
    non-printable keys (#1598)
  - [X11] Bugfix: Function keys were mapped to `GLFW_KEY_UNKNOWN` for some layout
    combinaitons (#1598)
+ - [X11] Bugfix: Keys pressed simultaneously with others were not always
+   reported (#1112,#1415,#1472,#1616)
  - [Wayland] Removed support for `wl_shell` (#1443)
  - [Wayland] Bugfix: The `GLFW_HAND_CURSOR` shape used the wrong image (#1432)
  - [Wayland] Bugfix: `CLOCK_MONOTONIC` was not correctly enabled
@@ -364,8 +366,10 @@ skills.
  - Eddie Ringle
  - Max Risuhin
  - Jorge Rodriguez
+ - Luca Rood
  - Ed Ropple
  - Aleksey Rybalkin
+ - Mikko Rytkönen
  - Riku Salminen
  - Brandon Schaefer
  - Sebastian Schuberth
diff --git a/src/x11_platform.h b/src/x11_platform.h
index 1d0687ef..62db6644 100644
--- a/src/x11_platform.h
+++ b/src/x11_platform.h
@@ -402,8 +402,9 @@ typedef struct _GLFWwindowX11
     // The last position the cursor was warped to by GLFW
     int             warpCursorPosX, warpCursorPosY;
 
-    // The time of the last KeyPress event
-    Time            lastKeyTime;
+    // The time of the last KeyPress event per keycode, for discarding
+    // duplicate key events generated for some keys by ibus
+    Time            keyPressTimes[256];
 
 } _GLFWwindowX11;
 
diff --git a/src/x11_window.c b/src/x11_window.c
index d56fe3da..726d7eaa 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -1265,16 +1265,20 @@ static void processEvent(XEvent *event)
 
             if (window->x11.ic)
             {
-                // HACK: Ignore duplicate key press events generated by ibus
-                //       These have the same timestamp as the original event
-                //       Corresponding release events are filtered out
-                //       implicitly by the GLFW key repeat logic
-                if (window->x11.lastKeyTime < event->xkey.time)
+                // HACK: Do not report the key press events duplicated by XIM
+                //       Duplicate key releases are filtered out implicitly by
+                //       the GLFW key repeat logic in _glfwInputKey
+                //       A timestamp per key is used to handle simultaneous keys
+                // NOTE: Always allow the first event for each key through
+                //       (the server never sends a timestamp of zero)
+                // NOTE: Timestamp difference is compared to handle wrap-around
+                Time diff = event->xkey.time - window->x11.keyPressTimes[keycode];
+                if (diff == event->xkey.time || (diff > 0 && diff < (1 << 31)))
                 {
                     if (keycode)
                         _glfwInputKey(window, key, keycode, GLFW_PRESS, mods);
 
-                    window->x11.lastKeyTime = event->xkey.time;
+                    window->x11.keyPressTimes[keycode] = event->xkey.time;
                 }
 
                 if (!filtered)