diff --git a/readme.md b/readme.md
index 6a480db..c4c99bf 100644
--- a/readme.md
+++ b/readme.md
@@ -2394,7 +2394,7 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 | Module | Description |
 |:--- |:--- |
 | `barrel_jack(cutout = false)` | Draw barrel power jack |
-| `block(size, colour, makes_cutout, cutouts)` | Draw a coloured cube to represent a random PCB component |
+| `block(size, colour, makes_cutout, cutouts, r = 0, rtop = 0)` | Draw a coloured cube to represent a random PCB component |
 | `buzzer(height, diameter, colour)` | Draw PCB buzzer with specified height, diameter and colour |
 | `chip(length, width, thickness, colour, cutout = false)` | Draw a coloured cube to represent a chip, or other rectangular component, or cylinder if width is zero |
 | `flat_flex(type, cutout = false)` | Draw flat flexistrip connector as used on RPI0 |
@@ -2560,7 +2560,7 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 | Module | Description |
 |:--- |:--- |
 | `barrel_jack(cutout = false)` | Draw barrel power jack |
-| `block(size, colour, makes_cutout, cutouts)` | Draw a coloured cube to represent a random PCB component |
+| `block(size, colour, makes_cutout, cutouts, r = 0, rtop = 0)` | Draw a coloured cube to represent a random PCB component |
 | `buzzer(height, diameter, colour)` | Draw PCB buzzer with specified height, diameter and colour |
 | `chip(length, width, thickness, colour, cutout = false)` | Draw a coloured cube to represent a chip, or other rectangular component, or cylinder if width is zero |
 | `flat_flex(type, cutout = false)` | Draw flat flexistrip connector as used on RPI0 |
diff --git a/tests/png/pcbs.png b/tests/png/pcbs.png
index e5ac8ab..8beaeee 100644
Binary files a/tests/png/pcbs.png and b/tests/png/pcbs.png differ
diff --git a/vitamins/pcb.scad b/vitamins/pcb.scad
index 95ae209..da0bbc2 100644
--- a/vitamins/pcb.scad
+++ b/vitamins/pcb.scad
@@ -1071,7 +1071,7 @@ module trimpot10(vertical, cutout = false) { //! Draw a ten turn trimpot
              }
 }
 
-module block(size, colour, makes_cutout, cutouts) //! Draw a coloured cube to represent a random PCB component
+module block(size, colour, makes_cutout, cutouts, r = 0, rtop = 0) //! Draw a coloured cube to represent a random PCB component
     if(cutouts) {
         if(makes_cutout)
              translate([-50, 0, size.z / 2 - panel_clearance])
@@ -1079,8 +1079,10 @@ module block(size, colour, makes_cutout, cutouts) //! Draw a coloured cube to re
     }
     else
         color(colour)
-            translate_z(size.z / 2)
-                cube(size, center = true);
+            if(rtop)
+                let($fn = 32) rounded_top_rectangle(size, r, rtop);
+            else
+                rounded_rectangle(size, r);
 
 module pcb_component(comp, cutouts = false, angle = undef) { //! Draw pcb component from description
     function show(comp, part) = (comp[3] == part || comp[3] == str("-",part)) && (!cutouts || angle == undef || angle == comp.z);
@@ -1116,7 +1118,7 @@ module pcb_component(comp, cutouts = false, angle = undef) { //! Draw pcb compon
         if(show(comp, "molex_usb_Ax1")) molex_usb_Ax1(cutouts);
         if(show(comp, "smd_led"))       smd_led(comp[4], comp[5], cutouts);
         if(show(comp, "7seg"))          let(z = param(6, 0)) translate_z(z) 7_segment_digits(comp[4], comp[5], pin_length = z + 3, cutout = cutouts);
-        if(show(comp, "block"))         block(size = [comp[4], comp[5], comp[6]], colour = comp[7], makes_cutout = param(8));
+        if(show(comp, "block"))         block(size = [comp[4], comp[5], comp[6]], colour = comp[7], makes_cutout = param(8), r = param(9, 0), rtop = param(10, 0));
         if(!cutouts) {
             // Components that don't have a cutout parameter go in this section
             if(show(comp, "button_6mm"))    square_button(button_6mm);
diff --git a/vitamins/pcbs.scad b/vitamins/pcbs.scad
index 4ec7a27..524abd9 100644
--- a/vitamins/pcbs.scad
+++ b/vitamins/pcbs.scad
@@ -864,7 +864,7 @@ XIAO = [
     [for(x = [0:6], y = [-1,1]) [x * 2.54 + 2.71, y * 3 * 2.54 + 9], // Inboard hole positions
      for(x = [0:6], y = [-1,1]) [x * 2.54 + 2.71, y * 9 + 9]],       // Hole positions on the edge, pad overlaps the inboard holes
     [ // components
-        [7.6, 9, 0, "block", 12.3, 12, 2.41, silver], // can
+        [7.6, 9, 0, "block", 12.3, 12, 2.41, silver, false, 0.3, 0.3], // can
         [21 + 1.76 - 7.35 / 2, 9, 0, "usb_C"],
     ],
     [] // accessories
@@ -913,7 +913,7 @@ ESP32_DOIT_V1 = let(l = 51.45, w = 28.33, pitch = inch(1), pins = 15, poffset =
       [l / 2 + poffset, w / 2 - pitch / 2, 0, "-2p54joiner", pins, 1],
       [l / 2 + poffset, w / 2 + pitch / 2, 0, "-2p54joiner", pins, 1],
       [1.75, w / 2, 180, "usb_uA" ],
-      [35,  w / 2, 0, "block", 17.7, 16, 3, silver], // can
+      [35,  w / 2, 0, "block", 17.7, 16, 3, silver, false, 0.3, 0.3], // can
       for(y=[-1,1]) [3.5,  y * 6.5, 0, "chip", 4,  3, 1.6, silver],   // Mock button surround
       for(y=[-1,1]) [3.5,  y * 6.5, 0, "chip", 1.8,0, 2.0, grey(20)], // Mock buttons
       for(y=[-1,1]) [21.6, y * 9,   0, "smd_led", LED0603, y < 0 ? "red" : "blue"],