diff --git a/printed/carriers.scad b/printed/carriers.scad
index 20a3248..f1b4af1 100644
--- a/printed/carriers.scad
+++ b/printed/carriers.scad
@@ -116,10 +116,10 @@ module MT3608_carrier_stl() { //! Generate the STL for an MT3608 carrier, two re
         difference() {
             hull() {
                 translate([offset, 0, height - eps / 2])
-                    rounded_rectangle([width, pcb_width - 2, eps], 1);
+                    rounded_rectangle([width, pcb_width - 2, eps], 1, true);
 
                 translate_z(eps / 2)
-                    rounded_rectangle([width, pcb_width - 2, eps], 1);
+                    rounded_rectangle([width, pcb_width - 2, eps], 1, true);
             }
             for(side = [-1, 1])
                 hull() {
diff --git a/readme.md b/readme.md
index 17ebd98..8a52d2a 100644
--- a/readme.md
+++ b/readme.md
@@ -6239,7 +6239,7 @@ Rectangle with rounded corners.
 | `rounded_cube_xy(size, r = 0, xy_center = false, z_center = false)` | Like `cube()` but corners rounded in XY plane and separate centre options for xy and z. |
 | `rounded_cube_xz(size, r = 0, xy_center = false, z_center = false)` | Like `cube()` but corners rounded in XZ plane and separate centre options for xy and z. |
 | `rounded_cube_yz(size, r = 0, xy_center = false, z_center = false)` | Like `cube()` but corners rounded in YX plane and separate centre options for xy and z. |
-| `rounded_rectangle(size, r, center = true, xy_center = true)` | Like `cube()` but corners rounded in XY plane and separate centre options for xy and z. |
+| `rounded_rectangle(size, r, center = false, xy_center = true)` | Like `cube()` but corners rounded in XY plane and separate centre options for xy and z. |
 | `rounded_square(size, r, center = true)` | Like `square()` but with with rounded corners |
 
 ![rounded_rectangle](tests/png/rounded_rectangle.png)
diff --git a/tests/BOM.scad b/tests/BOM.scad
index 99cadc1..ffea28c 100644
--- a/tests/BOM.scad
+++ b/tests/BOM.scad
@@ -46,7 +46,7 @@ module widget(thickness) {
 module widget_stl() {
     stl("widget")
         union() {
-            rounded_rectangle([30, 30, 3], 2);
+            rounded_rectangle([30, 30, 3], 2, true);
 
             render() insert_boss(insert, height, 2.2);
         }
diff --git a/tests/horiholes.scad b/tests/horiholes.scad
index c3ffeea..2913595 100644
--- a/tests/horiholes.scad
+++ b/tests/horiholes.scad
@@ -56,7 +56,7 @@ module horiholes_stl(t = thickness) {
         }
     if(t == thickness)
         translate([length / 2, 0])
-            rounded_rectangle([length + 2 * overlap_x, thickness + 2 * overlap_y, 2], 5);
+            rounded_rectangle([length + 2 * overlap_x, thickness + 2 * overlap_y, 2], 5, true);
 }
 
 module horiholes() {
diff --git a/tests/png/rounded_rectangle.png b/tests/png/rounded_rectangle.png
index f109a41..14dee80 100644
Binary files a/tests/png/rounded_rectangle.png and b/tests/png/rounded_rectangle.png differ
diff --git a/utils/core/rounded_rectangle.scad b/utils/core/rounded_rectangle.scad
index 205a009..bec9670 100644
--- a/utils/core/rounded_rectangle.scad
+++ b/utils/core/rounded_rectangle.scad
@@ -27,7 +27,7 @@ module rounded_square(size, r, center = true) //! Like `square()` but with with
     offset(r) offset(-r) square(size, center = center);
 }
 
-module rounded_rectangle(size, r, center = true, xy_center = true) //! Like `cube()` but corners rounded in XY plane and separate centre options for xy and z.
+module rounded_rectangle(size, r, center = false, xy_center = true) //! Like `cube()` but corners rounded in XY plane and separate centre options for xy and z.
 {
     extrude_if(size.z, center = center)
         rounded_square([size.x, size.y], r, xy_center);
diff --git a/vitamins/sk_bracket.scad b/vitamins/sk_bracket.scad
index 3f9fea5..823d8c4 100644
--- a/vitamins/sk_bracket.scad
+++ b/vitamins/sk_bracket.scad
@@ -62,7 +62,7 @@ module sk_bracket(type) { //! SK shaft support bracket
                     }
             for(x = [W / 2 - 2 * fillet, -W / 2 + 2 * fillet])
                 translate([x, G / 2, 0])
-                    rounded_rectangle([4 * fillet, G, L], fillet);
+                    rounded_rectangle([4 * fillet, G, L], fillet, true);
         }
 
         translate([0, -h, -L /2])
diff --git a/vitamins/transformer.scad b/vitamins/transformer.scad
index f92178c..a2c4287 100644
--- a/vitamins/transformer.scad
+++ b/vitamins/transformer.scad
@@ -56,10 +56,10 @@ module transformer(type) { //! Draw specified transformer
 
     }
 
-    color("white") {
+    color("white")
         translate_z(tx_lamination_height(type) / 2 + tx_bobbin_offset(type) / 2)
-            rounded_rectangle([tx_bobbin_width(type), tx_depth(type), tx_bobbin_height(type)], r = tx_bobbin_radius(type));
-    }
+            rounded_rectangle([tx_bobbin_width(type), tx_depth(type), tx_bobbin_height(type)], tx_bobbin_radius(type), true);
+
     terminal_height = tx_height(type) - tx_lamination_height(type);
 
     if(terminal_height)