diff --git a/button.go b/button.go
index f29d869..325a556 100644
--- a/button.go
+++ b/button.go
@@ -69,10 +69,9 @@ func (b *Button) setRect(x int, y int, width int, height int, winheight int) err
 	return b.sysData.setRect(x, y, width, height, winheight)
 }
 
-func (b *Button) preferredSize() (width int, height int, err error) {
+func (b *Button) preferredSize() (width int, height int) {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 
-	width, height = b.sysData.preferredSize()
-	return
+	return b.sysData.preferredSize()
 }
diff --git a/checkbox.go b/checkbox.go
index 5dfd3d1..2b2a71a 100644
--- a/checkbox.go
+++ b/checkbox.go
@@ -75,10 +75,9 @@ func (c *Checkbox) setRect(x int, y int, width int, height int, winheight int) e
 	return c.sysData.setRect(x, y, width, height, winheight)
 }
 
-func (c *Checkbox) preferredSize() (width int, height int, err error) {
+func (c *Checkbox) preferredSize() (width int, height int) {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	width, height = c.sysData.preferredSize()
-	return
+	return c.sysData.preferredSize()
 }
diff --git a/combobox.go b/combobox.go
index d42b353..85384be 100644
--- a/combobox.go
+++ b/combobox.go
@@ -154,10 +154,9 @@ func (c *Combobox) setRect(x int, y int, width int, height int, winheight int) e
 	return c.sysData.setRect(x, y, width, height, winheight)
 }
 
-func (c *Combobox) preferredSize() (width int, height int, err error) {
+func (c *Combobox) preferredSize() (width int, height int) {
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	width, height = c.sysData.preferredSize()
-	return
+	return c.sysData.preferredSize()
 }
diff --git a/control.go b/control.go
index 3f54afe..2513399 100644
--- a/control.go
+++ b/control.go
@@ -9,5 +9,5 @@ import (
 type Control interface {
 	make(window *sysData) error
 	setRect(x int, y int, width int, height int, winheight int) error
-	preferredSize() (width int, height int, err error)
+	preferredSize() (width int, height int)
 }
diff --git a/grid.go b/grid.go
index d960e92..fde6399 100644
--- a/grid.go
+++ b/grid.go
@@ -132,10 +132,7 @@ func (g *Grid) setRect(x int, y int, width int, height int, winheight int) error
 	// 2) get preferred sizes; compute row/column sizes
 	for row, xcol := range g.controls {
 		for col, c := range xcol {
-			w, h, err := c.preferredSize()
-			if err != nil {
-				return fmt.Errorf("error getting preferred size of control (%d,%d) in Grid.setRect(): %v", row, col, err)
-			}
+			w, h := c.preferredSize()
 			g.widths[row][col] = w
 			g.heights[row][col] = h
 			g.rowheights[row] = max(g.rowheights[row], h)
@@ -180,7 +177,7 @@ func (g *Grid) setRect(x int, y int, width int, height int, winheight int) error
 }
 
 // filling and stretchy are ignored for preferred size calculation
-func (g *Grid) preferredSize() (width int, height int, err error) {
+func (g *Grid) preferredSize() (width int, height int) {
 	g.lock.Lock()
 	defer g.lock.Unlock()
 
@@ -201,10 +198,7 @@ func (g *Grid) preferredSize() (width int, height int, err error) {
 	// 2) get preferred sizes; compute row/column sizes
 	for row, xcol := range g.controls {
 		for col, c := range xcol {
-			w, h, err := c.preferredSize()
-			if err != nil {
-				return 0, 0, fmt.Errorf("error getting preferred size of control (%d,%d) in Grid.setRect(): %v", row, col, err)
-			}
+			w, h := c.preferredSize()
 			g.widths[row][col] = w
 			g.heights[row][col] = h
 			g.rowheights[row] = max(g.rowheights[row], h)
@@ -218,5 +212,5 @@ func (g *Grid) preferredSize() (width int, height int, err error) {
 	for _, h := range g.rowheights {
 		height += h
 	}
-	return width, height, nil
+	return width, height
 }
diff --git a/label.go b/label.go
index 88e79af..be19949 100644
--- a/label.go
+++ b/label.go
@@ -63,10 +63,9 @@ func (l *Label) setRect(x int, y int, width int, height int, winheight int) erro
 	return l.sysData.setRect(x, y, width, height, winheight)
 }
 
-func (l *Label) preferredSize() (width int, height int, err error) {
+func (l *Label) preferredSize() (width int, height int) {
 	l.lock.Lock()
 	defer l.lock.Unlock()
 
-	width, height = l.sysData.preferredSize()
-	return
+	return l.sysData.preferredSize()
 }
diff --git a/lineedit.go b/lineedit.go
index 037c858..98617a5 100644
--- a/lineedit.go
+++ b/lineedit.go
@@ -75,10 +75,9 @@ func (l *LineEdit) setRect(x int, y int, width int, height int, winheight int) e
 	return l.sysData.setRect(x, y, width, height, winheight)
 }
 
-func (l *LineEdit) preferredSize() (width int, height int, err error) {
+func (l *LineEdit) preferredSize() (width int, height int) {
 	l.lock.Lock()
 	defer l.lock.Unlock()
 
-	width, height = l.sysData.preferredSize()
-	return
+	return l.sysData.preferredSize()
 }
diff --git a/listbox.go b/listbox.go
index 8bd54b1..6d5decc 100644
--- a/listbox.go
+++ b/listbox.go
@@ -139,10 +139,9 @@ func (l *Listbox) setRect(x int, y int, width int, height int, winheight int) er
 	return l.sysData.setRect(x, y, width, height, winheight)
 }
 
-func (l *Listbox) preferredSize() (width int, height int, err error) {
+func (l *Listbox) preferredSize() (width int, height int) {
 	l.lock.Lock()
 	defer l.lock.Unlock()
 
-	width, height = l.sysData.preferredSize()
-	return
+	return l.sysData.preferredSize()
 }
diff --git a/progressbar.go b/progressbar.go
index 4d41b28..4d80c94 100644
--- a/progressbar.go
+++ b/progressbar.go
@@ -56,10 +56,9 @@ func (p *ProgressBar) setRect(x int, y int, width int, height int, winheight int
 	return p.sysData.setRect(x, y, width, height, winheight)
 }
 
-func (p *ProgressBar) preferredSize() (width int, height int, err error) {
+func (p *ProgressBar) preferredSize() (width int, height int) {
 	p.lock.Lock()
 	defer p.lock.Unlock()
 
-	width, height = p.sysData.preferredSize()
-	return
+	return p.sysData.preferredSize()
 }
diff --git a/stack.go b/stack.go
index cfaf510..cb65bb5 100644
--- a/stack.go
+++ b/stack.go
@@ -91,10 +91,7 @@ func (s *Stack) setRect(x int, y int, width int, height int, winheight int) erro
 			nStretchy++
 			continue
 		}
-		w, h, err := c.preferredSize()
-		if err != nil {
-			return fmt.Errorf("error getting preferred size of control %d in Stack.setRect(): %v", i, err)
-		}
+		w, h := c.preferredSize()
 		if s.orientation == horizontal {			// all controls have same height
 			s.width[i] = w
 			s.height[i] = height
@@ -136,7 +133,7 @@ func (s *Stack) setRect(x int, y int, width int, height int, winheight int) erro
 }
 
 // The preferred size of a Stack is the sum of the preferred sizes of non-stretchy controls + (the number of stretchy controls * the largest preferred size among all stretchy controls).
-func (s *Stack) preferredSize() (width int, height int, err error) {
+func (s *Stack) preferredSize() (width int, height int) {
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
@@ -151,13 +148,10 @@ func (s *Stack) preferredSize() (width int, height int, err error) {
 	var maxswid, maxsht int
 
 	if len(s.controls) == 0 {		// no controls, so return emptiness
-		return 0, 0, nil
+		return 0, 0
 	}
 	for i, c := range s.controls {
-		w, h, err := c.preferredSize()
-		if err != nil {
-			return 0, 0, fmt.Errorf("error getting preferred size of control %d in Stack.preferredSize(): %v", i, err)
-		}
+		w, h := c.preferredSize()
 		if s.stretchy[i] {
 			nStretchy++
 			maxswid = max(maxswid, w)