diff --git a/src/backends/meta-input-settings-dummy.c b/src/backends/meta-input-settings-dummy.c
index ff980423c..74e6f429c 100644
--- a/src/backends/meta-input-settings-dummy.c
+++ b/src/backends/meta-input-settings-dummy.c
@@ -35,7 +35,7 @@ meta_input_settings_dummy_set_send_events (MetaInputSettings        *settings,
 static void
 meta_input_settings_dummy_set_matrix (MetaInputSettings  *settings,
                                       ClutterInputDevice *device,
-                                      gfloat              matrix[6])
+                                      const float         matrix[6])
 {
 }
 
diff --git a/src/backends/meta-input-settings-private.h b/src/backends/meta-input-settings-private.h
index 10de61d78..42ee0e0e6 100644
--- a/src/backends/meta-input-settings-private.h
+++ b/src/backends/meta-input-settings-private.h
@@ -81,7 +81,7 @@ struct _MetaInputSettingsClass
                               GDesktopDeviceSendEvents  mode);
   void (* set_matrix)        (MetaInputSettings  *settings,
                               ClutterInputDevice *device,
-                              gfloat              matrix[6]);
+                              const float         matrix[6]);
   void (* set_speed)         (MetaInputSettings  *settings,
                               ClutterInputDevice *device,
                               gdouble             speed);
diff --git a/src/backends/native/meta-input-settings-native.c b/src/backends/native/meta-input-settings-native.c
index 552fa84a4..18aafcc78 100644
--- a/src/backends/native/meta-input-settings-native.c
+++ b/src/backends/native/meta-input-settings-native.c
@@ -147,7 +147,7 @@ set_matrix (GTask *task)
 static void
 meta_input_settings_native_set_matrix (MetaInputSettings  *settings,
                                        ClutterInputDevice *device,
-                                       gfloat              matrix[6])
+                                       const float         matrix[6])
 {
   MetaInputSettingsNative *input_settings_native;
   cairo_matrix_t *dev_matrix;
diff --git a/src/backends/x11/meta-input-settings-x11.c b/src/backends/x11/meta-input-settings-x11.c
index a8b366315..96390285a 100644
--- a/src/backends/x11/meta-input-settings-x11.c
+++ b/src/backends/x11/meta-input-settings-x11.c
@@ -203,7 +203,7 @@ meta_input_settings_x11_set_send_events (MetaInputSettings        *settings,
 static void
 meta_input_settings_x11_set_matrix (MetaInputSettings  *settings,
                                     ClutterInputDevice *device,
-                                    gfloat              matrix[6])
+                                    const float         matrix[6])
 {
   MetaBackend *backend = meta_get_backend ();
   Display *xdisplay = meta_backend_x11_get_xdisplay (META_BACKEND_X11 (backend));