diff --git a/render.go b/render.go
index 7ae1ce8..b0e4ec9 100644
--- a/render.go
+++ b/render.go
@@ -211,7 +211,7 @@ func (o *Op) writeBlock(vars *renderVars) {
 
 	// Avoid empty paragraphs and "\n" in the output for text blocks.
 	if o.Data == "" && block.tagName == "p" && vars.tempBuf.Len() == 0 {
-		o.Data = "<br>"
+		o.Data = "<br/>"
 	}
 
 	if block.tagName != "" {
@@ -227,7 +227,7 @@ func (o *Op) writeBlock(vars *renderVars) {
 
 	vars.finalBuf.Write(vars.tempBuf.Bytes()) // Copy the temporary buffer to the final output.
 
-	vars.finalBuf.WriteString(o.Data) // Copy the data of the current Op (usually just "<br>" or blank).
+	vars.finalBuf.WriteString(o.Data) // Copy the data of the current Op (usually just "<br/>" or blank).
 
 	if block.tagName != "" {
 		closeTag(&vars.finalBuf, block.tagName)
diff --git a/render_test.go b/render_test.go
index b565ff3..c1c94af 100644
--- a/render_test.go
+++ b/render_test.go
@@ -15,7 +15,7 @@ func TestSimple(t *testing.T) {
 	}{
 		"empty": {
 			ops:  `[{"insert": "\n"}]`,
-			want: "<p><br></p>",
+			want: "<p><br/></p>",
 		},
 		"two paragraphs (single op)": {
 			ops:  `[{"insert": "line1\nline2\n"}]`,
@@ -23,7 +23,7 @@ func TestSimple(t *testing.T) {
 		},
 		"blank line": {
 			ops:  `[{"insert": "line1\n\nline3\n"}]`,
-			want: "<p>line1</p><p><br></p><p>line3</p>",
+			want: "<p>line1</p><p><br/></p><p>line3</p>",
 		},
 		"blockquote": {
 			ops:  `[{"insert": "bkqt"}, {"attributes": {"blockquote": true}, "insert": "\n"}]`,