diff --git a/html5/defs.json b/html5/defs.json
index d858664..71c624f 100644
--- a/html5/defs.json
+++ b/html5/defs.json
@@ -9,7 +9,7 @@
     {"name": "div"},
     {"name": "head"},
     {"name": "html"},
-    {"name": "img", "empty": true},
+    {"name": "img", "void": true},
     {"name": "li"},
     {"name": "span"},
     {"name": "title"},
diff --git a/internal/codegen/README.md b/internal/codegen/README.md
index c681b2e..27a3571 100644
--- a/internal/codegen/README.md
+++ b/internal/codegen/README.md
@@ -4,13 +4,13 @@ codegen reads JSON descriptions of HTML elements and attributes, and generates
 Go functions to create them.
 
 The input file consists of a JSON object like the following, which includes all
-options for attribute types and element emptiness:
+options for attribute types and element voidnesss:
 
 ```
 {
   "elements": [
     {"name": "div"},
-    {"name": "img", "empty": true},
+    {"name": "img", "void": true},
   ],
   "attributes": [
     {"name": "src", "type": "string"},
@@ -19,5 +19,5 @@ options for attribute types and element emptiness:
 }
 ```
 
-The `"empty"` key can be omitted from an element definition and defaults to
+The `"void"` key can be omitted from an element definition and defaults to
 `false`.
diff --git a/internal/codegen/codegen.go b/internal/codegen/codegen.go
index e30d7cb..063adb6 100644
--- a/internal/codegen/codegen.go
+++ b/internal/codegen/codegen.go
@@ -99,7 +99,7 @@ func (def AttribDef) Generate(qualified bool) string {
 
 type ElemDef struct {
     Name string `json:"name"`
-    Empty bool `json:"empty"`
+    Void bool `json:"void"`
 }
 
 func (def ElemDef) Generate(qualified bool) string {
@@ -132,7 +132,7 @@ func (def ElemDef) Generate(qualified bool) string {
         pkg = "hatmill."
     }
     template := parentTemplate
-    if def.Empty {
+    if def.Void {
         template = voidTemplate
     }
     return fmt.Sprintf(template, strings.Title(def.Name), def.Name, pkg)