diff --git a/ui/input/input.go b/ui/input/input.go
index 96ca0d2e..3a4c4b4e 100644
--- a/ui/input/input.go
+++ b/ui/input/input.go
@@ -10,8 +10,8 @@ type Queue interface {
 	Events(k Key) []Event
 }
 
-// Key is the stable identifier for an event handler. For a handler h, the
-// key is typically &h.
+// Key is the stable identifier for an event handler.
+// For a handler h, the key is typically &h.
 type Key interface{}
 
 // Event is the marker interface for input events.
diff --git a/ui/layout/layout.go b/ui/layout/layout.go
index f433855c..0a608d97 100644
--- a/ui/layout/layout.go
+++ b/ui/layout/layout.go
@@ -8,11 +8,15 @@ import (
 	"gioui.org/ui"
 )
 
+// Constraints represent a set of acceptable ranges for
+// a widget's width and height.
 type Constraints struct {
 	Width  Constraint
 	Height Constraint
 }
 
+// Constraint is a range of acceptable sizes in a single
+// dimension.
 type Constraint struct {
 	Min, Max int
 }