diff --git a/tools/lib/template_parser.py b/tools/lib/template_parser.py
index eb3d507960..4b94a49d81 100644
--- a/tools/lib/template_parser.py
+++ b/tools/lib/template_parser.py
@@ -301,7 +301,21 @@ def validate(fn: Optional[str] = None, text: Optional[str] = None, check_indent:
 def is_special_html_tag(s: str, tag: str) -> bool:
     return tag in ['link', 'meta', '!DOCTYPE']
 
+OPTIONAL_CLOSING_TAGS = [
+    'br',
+    'circle',
+    'hr',
+    'img',
+    'input',
+    'path',
+    'polygon',
+]
+
 def is_self_closing_html_tag(s: Text, tag: Text) -> bool:
+    if s.endswith('/>'):
+        if tag in OPTIONAL_CLOSING_TAGS:
+            return True
+        raise TokenizationException('Singleton tag not allowed', tag)
     self_closing_tag = tag in [
         'area',
         'base',
@@ -316,8 +330,9 @@ def is_self_closing_html_tag(s: Text, tag: Text) -> bool:
         'track',
         'wbr',
     ]
-    singleton_tag = s.endswith('/>')
-    return self_closing_tag or singleton_tag
+    if self_closing_tag:
+        return True
+    return False
 
 def is_django_block_tag(tag: str) -> bool:
     return tag in [
diff --git a/tools/tests/test_html_branches.py b/tools/tests/test_html_branches.py
index ccce328923..45dbafad32 100644
--- a/tools/tests/test_html_branches.py
+++ b/tools/tests/test_html_branches.py
@@ -41,7 +41,7 @@ class TestHtmlBranches(unittest.TestCase):
                 <link rel="stylesheet" href="style.css" />
             </head>
             <body>
-                <p>Hello<br />world!</p>
+                <p>Hello<br>world!</p>
                 <p>Goodbye<!-- test -->world!</p>
             </body>
             </html>
@@ -83,7 +83,7 @@ class TestHtmlBranches(unittest.TestCase):
                 <link rel="stylesheet" href="style.css" />
             </head>
             <body>
-                <p>Hello<br />world!</p>
+                <p>Hello<br>world!</p>
                 <p>Goodbye<!-- test -->world!</p>
             </body>
             </html>
diff --git a/tools/tests/test_pretty_print.py b/tools/tests/test_pretty_print.py
index ec3f620221..efc250af12 100644
--- a/tools/tests/test_pretty_print.py
+++ b/tools/tests/test_pretty_print.py
@@ -20,7 +20,7 @@ BAD_HTML = """
         <link rel="stylesheet" href="style.css" />
     </head>
     <body>
-      <div><p>Hello<br />world!</p></div>
+      <div><p>Hello<br>world!</p></div>
         <p>Goodbye<!-- test -->world!</p>
         <table>
            <tr>
@@ -52,7 +52,7 @@ GOOD_HTML = """
         <link rel="stylesheet" href="style.css" />
     </head>
     <body>
-        <div><p>Hello<br />world!</p></div>
+        <div><p>Hello<br>world!</p></div>
         <p>Goodbye<!-- test -->world!</p>
         <table>
             <tr>
@@ -338,7 +338,7 @@ BAD_HTML13 = """
     {{#if this.is_realm_emoji}}
       <img src="{{this.url}}" class="emoji" />
     {{else}}
-      <div/>
+      <br>
     {{/if}}
   {{/if}}
   <div>{{this.count}}</div>
@@ -353,7 +353,7 @@ GOOD_HTML13 = """
         {{#if this.is_realm_emoji}}
         <img src="{{this.url}}" class="emoji" />
         {{else}}
-        <div/>
+        <br>
         {{/if}}
     {{/if}}
     <div>{{this.count}}</div>
diff --git a/tools/tests/test_template_parser.py b/tools/tests/test_template_parser.py
index 894058251f..5928101e47 100644
--- a/tools/tests/test_template_parser.py
+++ b/tools/tests/test_template_parser.py
@@ -249,7 +249,7 @@ class ParserTest(unittest.TestCase):
         self.assertEqual(token.kind, 'html_start')
         self.assertEqual(token.tag, 'a')
 
-        tag = '<br />bla'
+        tag = '<br>bla'
         token = tokenize(tag)[0]
         self.assertEqual(token.kind, 'html_singleton')
         self.assertEqual(token.tag, 'br')
