diff --git a/src/cairo-region.c b/src/cairo-region.c
index 2ec3941c1..3f2b97896 100644
--- a/src/cairo-region.c
+++ b/src/cairo-region.c
@@ -121,7 +121,7 @@ slim_hidden_def (cairo_region_create);
  * Since: 1.10
  **/
 cairo_region_t *
-cairo_region_create_rectangle (cairo_rectangle_int_t *rectangle)
+cairo_region_create_rectangle (const cairo_rectangle_int_t *rectangle)
 {
     cairo_region_t *region;
 
@@ -335,7 +335,7 @@ slim_hidden_def (cairo_region_subtract);
  **/
 cairo_status_t
 cairo_region_subtract_rectangle (cairo_region_t *dst,
-				 cairo_rectangle_int_t *rectangle)
+				 const cairo_rectangle_int_t *rectangle)
 {
     cairo_status_t status = CAIRO_STATUS_SUCCESS;
     pixman_region32_t region;
diff --git a/src/cairo.h b/src/cairo.h
index 025ca6c97..917d36404 100644
--- a/src/cairo.h
+++ b/src/cairo.h
@@ -2368,7 +2368,7 @@ cairo_public cairo_region_t *
 cairo_region_create (void);
 
 cairo_public cairo_region_t *
-cairo_region_create_rectangle (cairo_rectangle_int_t *rectangle);
+cairo_region_create_rectangle (const cairo_rectangle_int_t *rectangle);
 
 cairo_public cairo_region_t *
 cairo_region_copy (cairo_region_t *original);
@@ -2409,7 +2409,7 @@ cairo_region_subtract (cairo_region_t *dst, cairo_region_t *other);
 
 cairo_public cairo_status_t
 cairo_region_subtract_rectangle (cairo_region_t *dst,
-				 cairo_rectangle_int_t *rectangle);
+				 const cairo_rectangle_int_t *rectangle);
 
 cairo_public cairo_status_t
 cairo_region_intersect (cairo_region_t *dst, cairo_region_t *other);