diff --git a/shapes3d.scad b/shapes3d.scad
index 24ddd418..57d26f8e 100644
--- a/shapes3d.scad
+++ b/shapes3d.scad
@@ -2473,9 +2473,9 @@ module zcyl(
 // Example: Mixing chamfers and roundings
 //   back_half()
 //     tube(ir=10,or=20,h=30, ochamfer1=-5,irounding1=-3, orounding2=6, ichamfer2=2);
-// Example: Tube with hexagonal hole circumscribing its diameter
-//   tube(od=22, id=9, h=10, $fn=48, ifn=6, circum=true);
-//   half_of(v=[-1,1]) color("lightblue") cyl(d=9, h=12);
+// Example: Tube with a square hole circumscribing its diameter
+//   tube(od=22, id=9, h=10, $fn=48, ifn=4, circum=true);
+//   half_of(v=[-1,1]) color("lightblue") cyl(d=9, h=12, $fn=32);
 // Example: Round ended hexagonal tube using `rounding_fn` to get sufficient facets on the roundings
 //   tube(or=10, ir=7, h=10, $fn=6, rounding_fn=64, rounding=1.3, teardrop=true);
 
@@ -2486,7 +2486,8 @@ function tube(
     ir1, ir2, id1, id2,
     realign=false, l, length, height,
     anchor, spin=0, orient=UP, orounding1,irounding1,orounding2,irounding2,rounding1,rounding2,rounding,
-    ochamfer1,ichamfer1,ochamfer2,ichamfer2,chamfer1,chamfer2,chamfer,irounding,ichamfer,orounding,ochamfer, teardrop=false
+    ochamfer1,ichamfer1,ochamfer2,ichamfer2,chamfer1,chamfer2,chamfer,irounding,ichamfer,orounding,ochamfer, teardrop=false, shift=[0,0],
+    ifn, rounding_fn, circum=false
 ) = no_function("tube");
 
 
@@ -2500,7 +2501,6 @@ module tube(
     anchor, spin=0, orient=UP, orounding1,irounding1,orounding2,irounding2,rounding1,rounding2,rounding,
     ochamfer1,ichamfer1,ochamfer2,ichamfer2,chamfer1,chamfer2,chamfer,irounding,ichamfer,orounding,ochamfer, teardrop=false, shift=[0,0],
     ifn, rounding_fn, circum=false
-    
 ) {
     h = one_defined([h,l,height,length],"h,l,height,length",dflt=1);
     orr1 = get_radius(r1=or1, r=or, d1=od1, d=od, dflt=undef);