diff --git a/beziers.scad b/beziers.scad
index af9675e..23735c9 100644
--- a/beziers.scad
+++ b/beziers.scad
@@ -762,8 +762,10 @@ module linear_sweep_bezier(bezier, height=100, splinesteps=16, N=3, center, conv
     maxy = max([for (pt = bezier) abs(pt[1])]);
     anchor = get_anchor(anchor,center,BOT,BOT);
     attachable(anchor,spin,orient, size=[maxx*2,maxy*2,height]) {
-        linear_extrude(height=height, center=true, convexity=convexity, twist=twist, slices=slices, scale=scale) {
-            bezier_polygon(bezier, splinesteps=splinesteps, N=N);
+        if (height > 0) {
+            linear_extrude(height=height, center=true, convexity=convexity, twist=twist, slices=slices, scale=scale) {
+                bezier_polygon(bezier, splinesteps=splinesteps, N=N);
+            }
         }
         children();
     }
diff --git a/paths.scad b/paths.scad
index ac95666..bdb05fb 100644
--- a/paths.scad
+++ b/paths.scad
@@ -779,12 +779,14 @@ module modulated_circle(r, sines=[10], d)
 //   extrude_from_to([0,0,0], [10,20,30], convexity=4, twist=360, scale=3.0, slices=40) {
 //       xcopies(3) circle(3, $fn=32);
 //   }
-module extrude_from_to(pt1, pt2, convexity=undef, twist=undef, scale=undef, slices=undef) {
+module extrude_from_to(pt1, pt2, convexity, twist, scale, slices) {
     rtp = xyz_to_spherical(pt2-pt1);
     translate(pt1) {
         rotate([0, rtp[2], rtp[1]]) {
-            linear_extrude(height=rtp[0], convexity=convexity, center=false, slices=slices, twist=twist, scale=scale) {
-                children();
+            if (rtp[0] > 0) {
+                linear_extrude(height=rtp[0], convexity=convexity, center=false, slices=slices, twist=twist, scale=scale) {
+                    children();
+                }
             }
         }
     }
@@ -895,8 +897,10 @@ module path_extrude(path, convexity=10, clipsize=100) {
             translate(pt1) {
                 Qrot(q) {
                     down(clipsize/2/2) {
-                        linear_extrude(height=dist+clipsize/2, convexity=convexity) {
-                            children();
+                        if ((dist+clipsize/2) > 0) {
+                            linear_extrude(height=dist+clipsize/2, convexity=convexity) {
+                                children();
+                            }
                         }
                     }
                 }
diff --git a/primitives.scad b/primitives.scad
index 8386094..98d6367 100644
--- a/primitives.scad
+++ b/primitives.scad
@@ -108,8 +108,10 @@ module cube(size=1, center, anchor, spin=0, orient=UP)
     anchor = get_anchor(anchor, center, ALLNEG, ALLNEG);
     size = scalar_vec3(size);
     attachable(anchor,spin,orient, size=size) {
-        linear_extrude(height=size.z, center=true, convexity=2) {
-            square([size.x,size.y], center=true);
+        if (size.z > 0) {
+            linear_extrude(height=size.z, center=true, convexity=2) {
+                square([size.x,size.y], center=true);
+            }
         }
         children();
     }
@@ -189,14 +191,18 @@ module cylinder(h, r1, r2, center, l, r, d, d1, d2, anchor, spin=0, orient=UP)
     l = first_defined([h, l, 1]);
     sides = segs(max(r1,r2));
     attachable(anchor,spin,orient, r1=r1, r2=r2, l=l) {
-        if(r1>r2) {
-            linear_extrude(height=l, center=true, convexity=2, scale=r2/r1) {
-                circle(r=r1);
+        if (r1 > r2) {
+            if (l > 0) {
+                linear_extrude(height=l, center=true, convexity=2, scale=r2/r1) {
+                    circle(r=r1);
+                }
             }
         } else {
             zflip() {
-                linear_extrude(height=l, center=true, convexity=2, scale=r1/r2) {
-                    circle(r=r2);
+                if (l > 0) {
+                    linear_extrude(height=l, center=true, convexity=2, scale=r1/r2) {
+                        circle(r=r2);
+                    }
                 }
             }
         }
diff --git a/shapes.scad b/shapes.scad
index c219731..0c63a81 100644
--- a/shapes.scad
+++ b/shapes.scad
@@ -81,7 +81,7 @@ module cuboid(
         c2 = vmul(corner,c/2);
         $fn = is_finite(chamfer)? 4 : segs(r);
         translate(vmul(corner, size/2-c)) {
-            if (cnt == 0) {
+            if (cnt == 0 || approx(r,0)) {
                 translate(c2) cube(c, center=true);
             } else if (cnt == 1) {
                 if (e.x) right(c2.x) xcyl(l=c.x, r=r);
@@ -120,6 +120,12 @@ module cuboid(
 
     size = scalar_vec3(size);
     edges = edges(edges, except=except_edges);
+    assert(is_vector(size,3));
+    assert(is_undef(chamfer) || is_finite(chamfer));
+    assert(is_undef(rounding) || is_finite(rounding));
+    assert(is_undef(p1) || is_vector(p1));
+    assert(is_undef(p2) || is_vector(p2));
+    assert(is_bool(trimcorners));
     if (!is_undef(p1)) {
         if (!is_undef(p2)) {
             translate(pointlist_bounds([p1,p2])[0]) {
@@ -131,19 +137,19 @@ module cuboid(
             }
         }
     } else {
-        if (chamfer != undef) {
+        if (is_finite(chamfer)) {
             if (any(edges[0])) assert(chamfer <= size.y/2 && chamfer <=size.z/2, "chamfer must be smaller than half the cube length or height.");
             if (any(edges[1])) assert(chamfer <= size.x/2 && chamfer <=size.z/2, "chamfer must be smaller than half the cube width or height.");
             if (any(edges[2])) assert(chamfer <= size.x/2 && chamfer <=size.y/2, "chamfer must be smaller than half the cube width or length.");
         }
-        if (rounding != undef) {
+        if (is_finite(rounding)) {
             if (any(edges[0])) assert(rounding <= size.y/2 && rounding<=size.z/2, "rounding radius must be smaller than half the cube length or height.");
             if (any(edges[1])) assert(rounding <= size.x/2 && rounding<=size.z/2, "rounding radius must be smaller than half the cube width or height.");
             if (any(edges[2])) assert(rounding <= size.x/2 && rounding<=size.y/2, "rounding radius must be smaller than half the cube width or length.");
         }
         majrots = [[0,90,0], [90,0,0], [0,0,0]];
         attachable(anchor,spin,orient, size=size) {
-            if (chamfer != undef) {
+            if (is_finite(chamfer) && !approx(chamfer,0)) {
                 if (edges == EDGES_ALL && trimcorners) {
                     if (chamfer<0) {
                         cube(size, center=true) {
@@ -212,7 +218,7 @@ module cuboid(
                         corner_shape([ 1, 1, 1]);
                     }
                 }
-            } else if (rounding != undef) {
+            } else if (is_finite(rounding) && !approx(rounding,0)) {
                 sides = quantup(segs(rounding),4);
                 if (edges == EDGES_ALL) {
                     if(rounding<0) {
@@ -506,8 +512,10 @@ module right_triangle(size=[1, 1, 1], center, anchor, spin=0, orient=UP)
     size = scalar_vec3(size);
     anchor = get_anchor(anchor, center, ALLNEG, ALLNEG);
     attachable(anchor,spin,orient, size=size) {
-        linear_extrude(height=size.z, convexity=2, center=true) {
-            polygon([[-size.x/2,-size.y/2], [-size.x/2,size.y/2], [size.x/2,-size.y/2]]);
+        if (size.z > 0) {
+            linear_extrude(height=size.z, convexity=2, center=true) {
+                polygon([[-size.x/2,-size.y/2], [-size.x/2,size.y/2], [size.x/2,-size.y/2]]);
+            }
         }
         children();
     }
@@ -1389,8 +1397,10 @@ module teardrop(r=undef, d=undef, l=undef, h=undef, ang=45, cap_h=undef, anchor=
     size = [r*2,l,r*2];
     attachable(anchor,spin,orient, size=size) {
         rot(from=UP,to=FWD) {
-            linear_extrude(height=l, center=true, slices=2) {
-                teardrop2d(r=r, ang=ang, cap_h=cap_h);
+            if (l > 0) {
+                linear_extrude(height=l, center=true, slices=2) {
+                    teardrop2d(r=r, ang=ang, cap_h=cap_h);
+                }
             }
         }
         children();
@@ -1561,12 +1571,14 @@ module interior_fillet(l=1.0, r, ang=90, overlap=0.01, d, anchor=FRONT+LEFT, spi
     steps = ceil(segs(r)*ang/360);
     step = ang/steps;
     attachable(anchor,spin,orient, size=[r,r,l]) {
-        linear_extrude(height=l, convexity=4, center=true) {
-            path = concat(
-                [[0,0]],
-                [for (i=[0:1:steps]) let(a=270-i*step) r*[cos(a),sin(a)]+[dy,r]]
-            );
-            translate(-[r,r]/2) polygon(path);
+        if (l > 0) {
+            linear_extrude(height=l, convexity=4, center=true) {
+                path = concat(
+                    [[0,0]],
+                    [for (i=[0:1:steps]) let(a=270-i*step) r*[cos(a),sin(a)]+[dy,r]]
+                );
+                translate(-[r,r]/2) polygon(path);
+            }
         }
         children();
     }
diff --git a/shapes2d.scad b/shapes2d.scad
index 4eda015..3401250 100644
--- a/shapes2d.scad
+++ b/shapes2d.scad
@@ -298,7 +298,7 @@ module stroke(
                         }
                     } else {
                         rotate([90,0,endcap_angle1]) {
-                            linear_extrude(height=widths[0], center=true, convexity=convexity) {
+                            linear_extrude(height=max(widths[0],0.001), center=true, convexity=convexity) {
                                 polygon(endcap_shape1);
                             }
                         }
@@ -318,7 +318,7 @@ module stroke(
                         }
                     } else {
                         rotate([90,0,endcap_angle2]) {
-                            linear_extrude(height=select(widths,-1), center=true, convexity=convexity) {
+                            linear_extrude(height=max(select(widths,-1),0.001), center=true, convexity=convexity) {
                                 polygon(endcap_shape2);
                             }
                         }
diff --git a/version.scad b/version.scad
index 189eb41..12852f3 100644
--- a/version.scad
+++ b/version.scad
@@ -8,7 +8,7 @@
 //////////////////////////////////////////////////////////////////////
 
 
-BOSL_VERSION = [2,0,469];
+BOSL_VERSION = [2,0,471];
 
 
 // Section: BOSL Library Version Functions