diff --git a/glfw/cocoa_monitor.m b/glfw/cocoa_monitor.m
index 4f4be9158..eab8ff9d0 100644
--- a/glfw/cocoa_monitor.m
+++ b/glfw/cocoa_monitor.m
@@ -618,9 +618,13 @@ GLFWvidmode* _glfwPlatformGetVideoModes(_GLFWmonitor* monitor, int* count)
     return result;
 }
 
-void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode *mode)
+bool _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode *mode)
 {
     CGDisplayModeRef native = CGDisplayCopyDisplayMode(monitor->ns.displayID);
+    if (!native) {
+        _glfwInputError(GLFW_PLATFORM_ERROR, "Cocoa: Failed to query display mode");
+        return false;
+    }
     *mode = vidmodeFromCGDisplayMode(native, monitor->ns.fallbackRefreshRate);
     CGDisplayModeRelease(native);
 }
diff --git a/glfw/internal.h b/glfw/internal.h
index 428839d9e..7af6ec000 100644
--- a/glfw/internal.h
+++ b/glfw/internal.h
@@ -686,7 +686,7 @@ void _glfwPlatformGetMonitorContentScale(_GLFWmonitor* monitor,
                                          float* xscale, float* yscale);
 void _glfwPlatformGetMonitorWorkarea(_GLFWmonitor* monitor, int* xpos, int* ypos, int *width, int *height);
 GLFWvidmode* _glfwPlatformGetVideoModes(_GLFWmonitor* monitor, int* count);
-void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode);
+bool _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode);
 bool _glfwPlatformGetGammaRamp(_GLFWmonitor* monitor, GLFWgammaramp* ramp);
 void _glfwPlatformSetGammaRamp(_GLFWmonitor* monitor, const GLFWgammaramp* ramp);
 
diff --git a/glfw/monitor.c b/glfw/monitor.c
index c25148e3c..423d2c83b 100644
--- a/glfw/monitor.c
+++ b/glfw/monitor.c
@@ -445,7 +445,7 @@ GLFWAPI const GLFWvidmode* glfwGetVideoMode(GLFWmonitor* handle)
 
     _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
 
-    _glfwPlatformGetVideoMode(monitor, &monitor->currentMode);
+    if (!_glfwPlatformGetVideoMode(monitor, &monitor->currentMode)) return NULL;
     return &monitor->currentMode;
 }
 
diff --git a/glfw/wl_monitor.c b/glfw/wl_monitor.c
index 5b3a7f149..15cc0bc14 100644
--- a/glfw/wl_monitor.c
+++ b/glfw/wl_monitor.c
@@ -195,9 +195,13 @@ GLFWvidmode* _glfwPlatformGetVideoModes(_GLFWmonitor* monitor, int* found)
     return monitor->modes;
 }
 
-void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode)
+bool _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode)
 {
-    *mode = monitor->modes[monitor->wl.currentMode];
+    if (monitor->modeCount > monitor->wl.currentMode) {
+        *mode = monitor->modes[monitor->wl.currentMode];
+        return true;
+    }
+    return false;
 }
 
 bool _glfwPlatformGetGammaRamp(_GLFWmonitor* monitor UNUSED, GLFWgammaramp* ramp UNUSED)
diff --git a/glfw/x11_monitor.c b/glfw/x11_monitor.c
index 26b42e293..6c594fbe8 100644
--- a/glfw/x11_monitor.c
+++ b/glfw/x11_monitor.c
@@ -494,8 +494,8 @@ GLFWvidmode* _glfwPlatformGetVideoModes(_GLFWmonitor* monitor, int* count)
     return result;
 }
 
-void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode)
-{
+bool _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode) {
+    bool ok = false;
     if (_glfw.x11.randr.available && !_glfw.x11.randr.monitorBroken)
     {
         XRRScreenResources* sr =
@@ -505,8 +505,10 @@ void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode)
         if (ci)
         {
             const XRRModeInfo* mi = getModeInfo(sr, ci->mode);
-            if (mi)  // mi can be NULL if the monitor has been disconnected
+            if (mi) { // mi can be NULL if the monitor has been disconnected
                 *mode = vidmodeFromModeInfo(mi, ci);
+                ok = true;
+            }
 
             XRRFreeCrtcInfo(ci);
         }
@@ -515,6 +517,7 @@ void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode)
     }
     else
     {
+        ok = true;
         mode->width = DisplayWidth(_glfw.x11.display, _glfw.x11.screen);
         mode->height = DisplayHeight(_glfw.x11.display, _glfw.x11.screen);
         mode->refreshRate = 0;
@@ -522,6 +525,7 @@ void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode)
         _glfwSplitBPP(DefaultDepth(_glfw.x11.display, _glfw.x11.screen),
                       &mode->redBits, &mode->greenBits, &mode->blueBits);
     }
+    return ok;
 }
 
 bool _glfwPlatformGetGammaRamp(_GLFWmonitor* monitor, GLFWgammaramp* ramp)
diff --git a/kitty/glfw.c b/kitty/glfw.c
index 1f73c3a9f..082bf03aa 100644
--- a/kitty/glfw.c
+++ b/kitty/glfw.c
@@ -1823,6 +1823,7 @@ static PyObject*
 primary_monitor_size(PYNOARG) {
     GLFWmonitor* monitor = glfwGetPrimaryMonitor();
     const GLFWvidmode* mode = glfwGetVideoMode(monitor);
+    if (mode == NULL) { PyErr_SetString(PyExc_ValueError, "Failed to get video mode for primary monitor"); return NULL; }
     return Py_BuildValue("ii", mode->width, mode->height);
 }