diff --git a/hw/input/tsc2005.c b/hw/input/tsc2005.c
index 14698ce109..555b677173 100644
--- a/hw/input/tsc2005.c
+++ b/hw/input/tsc2005.c
@@ -523,7 +523,7 @@ void *tsc2005_init(qemu_irq pintdav)
  * from the touchscreen.  Assuming 12-bit precision was used during
  * tslib calibration.
  */
-void tsc2005_set_transform(void *opaque, MouseTransformInfo *info)
+void tsc2005_set_transform(void *opaque, const MouseTransformInfo *info)
 {
     TSC2005State *s = (TSC2005State *) opaque;
 
diff --git a/hw/input/tsc210x.c b/hw/input/tsc210x.c
index df7313db5d..fdd5ff87d9 100644
--- a/hw/input/tsc210x.c
+++ b/hw/input/tsc210x.c
@@ -1176,8 +1176,7 @@ I2SCodec *tsc210x_codec(uWireSlave *chip)
  * from the touchscreen.  Assuming 12-bit precision was used during
  * tslib calibration.
  */
-void tsc210x_set_transform(uWireSlave *chip,
-                MouseTransformInfo *info)
+void tsc210x_set_transform(uWireSlave *chip, const MouseTransformInfo *info)
 {
     TSC210xState *s = (TSC210xState *) chip->opaque;
 #if 0
diff --git a/include/hw/input/tsc2xxx.h b/include/hw/input/tsc2xxx.h
index 5b76ebc177..00eca17674 100644
--- a/include/hw/input/tsc2xxx.h
+++ b/include/hw/input/tsc2xxx.h
@@ -30,12 +30,12 @@ uWireSlave *tsc2102_init(qemu_irq pint);
 uWireSlave *tsc2301_init(qemu_irq penirq, qemu_irq kbirq, qemu_irq dav);
 I2SCodec *tsc210x_codec(uWireSlave *chip);
 uint32_t tsc210x_txrx(void *opaque, uint32_t value, int len);
-void tsc210x_set_transform(uWireSlave *chip, MouseTransformInfo *info);
+void tsc210x_set_transform(uWireSlave *chip, const MouseTransformInfo *info);
 void tsc210x_key_event(uWireSlave *chip, int key, int down);
 
 /* tsc2005.c */
 void *tsc2005_init(qemu_irq pintdav);
 uint32_t tsc2005_txrx(void *opaque, uint32_t value, int len);
-void tsc2005_set_transform(void *opaque, MouseTransformInfo *info);
+void tsc2005_set_transform(void *opaque, const MouseTransformInfo *info);
 
 #endif