diff -r 84c2582329b0 src/video/x11/SDL_x11xinput2.c
--- a/src/video/x11/SDL_x11xinput2.c	Thu May 24 07:30:24 2018 -0700
+++ b/src/video/x11/SDL_x11xinput2.c	Thu May 31 12:52:40 2018 -0500
@@ -83,16 +83,8 @@
     for (i = 0; i < videodata->numwindows; i++) {
         SDL_WindowData *d = videodata->windowlist[i];
         if (d->xwindow == window) {
-            if (d->window->w == 1) {
-                *out_x = 0.5f;
-            } else {
-                *out_x = in_x / (d->window->w - 1);
-            }
-            if (d->window->h == 1) {
-                *out_y = 0.5f;
-            } else {
-                *out_y = in_y / (d->window->h - 1);
-            }
+            *out_x = in_x / d->window->w;
+            *out_y = in_y / d->window->h;
             return;
         }
     }