diff --git a/dix/devices.c b/dix/devices.c
index 9b6faee23..291b76773 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -112,8 +112,8 @@ DeviceSetTransform(DeviceIntPtr dev, float *transform_data)
      *  Transform is the user supplied (affine) transform
      *  InvScale scales coordinates back up into their native range
      */
-    sx = dev->valuator->axes[0].max_value - dev->valuator->axes[0].min_value;
-    sy = dev->valuator->axes[1].max_value - dev->valuator->axes[1].min_value;
+    sx = dev->valuator->axes[0].max_value - dev->valuator->axes[0].min_value + 1;
+    sy = dev->valuator->axes[1].max_value - dev->valuator->axes[1].min_value + 1;
 
     /* invscale */
     pixman_f_transform_init_scale(&scale, sx, sy);
diff --git a/dix/getevents.c b/dix/getevents.c
index ac0ccb28f..51d4fd4da 100644
--- a/dix/getevents.c
+++ b/dix/getevents.c
@@ -298,11 +298,11 @@ rescaleValuatorAxis(double coord, AxisInfoPtr from, AxisInfoPtr to,
 
     if (from && from->min_value < from->max_value) {
         fmin = from->min_value;
-        fmax = from->max_value;
+        fmax = from->max_value + 1;
     }
     if (to && to->min_value < to->max_value) {
         tmin = to->min_value;
-        tmax = to->max_value;
+        tmax = to->max_value + 1;
     }
 
     if (fmin == tmin && fmax == tmax)
@@ -924,9 +924,9 @@ scale_to_desktop(DeviceIntPtr dev, ValuatorMask *mask,
 
     /* scale x&y to desktop coordinates */
     *screenx = rescaleValuatorAxis(x, dev->valuator->axes + 0, NULL,
-                                   screenInfo.x, screenInfo.width - 1);
+                                   screenInfo.x, screenInfo.width);
     *screeny = rescaleValuatorAxis(y, dev->valuator->axes + 1, NULL,
-                                   screenInfo.y, screenInfo.height - 1);
+                                   screenInfo.y, screenInfo.height);
 
     *devx = x;
     *devy = y;
@@ -1366,6 +1366,12 @@ QueuePointerEvents(DeviceIntPtr device, int type,
  * is the last coordinate on the first screen and must be rescaled for the
  * event to be m. XI2 clients that do their own coordinate mapping would
  * otherwise interpret the position of the device elsewere to the cursor.
+ * However, this scaling leads to losses:
+ * if we have two ScreenRecs we scale from e.g. [0..44704]  (Wacom I4) to
+ * [0..2048[. that gives us 2047.954 as desktop coord, or the per-screen
+ * coordinate 1023.954. Scaling that back into the device coordinate range
+ * gives us 44703. So off by one device unit. It's a bug, but we'll have to
+ * live with it because with all this scaling, we just cannot win.
  *
  * @return the number of events written into events.
  */