diff --git a/syntax.json b/syntax.json
index fbdb5f3..e8dad92 100644
--- a/syntax.json
+++ b/syntax.json
@@ -163,6 +163,15 @@
       }
     ]
   },
+  {
+    "language": "JSON5",
+    "markers": [
+      {
+        "type": "line",
+        "pattern": "//"
+      }
+    ]
+  },
   {
     "language": "Julia",
     "markers": [
diff --git a/tests/test_new.diff b/tests/test_new.diff
index c1c81d6..f8de332 100644
--- a/tests/test_new.diff
+++ b/tests/test_new.diff
@@ -292,3 +292,17 @@ index 0000000..525e25d
 +    #  This function should probably do something more interesting
 +    #  labels: help wanted
 +}
+diff --git a/tests/example_file.r b/tests/config.json5
+new file mode 100644
+index 0000000..525f56e
+--- /dev/null
++++ b/tests/example_file.json5
+@@ -0,0 +1,7 @@
++{
++  "myConfig": [
++ // GitRepository where 'Git release/tag' matches 'Helm' version
++ "itIsWonderful",
++ // TODO: Delete this line from the codebase 
++ "butItHasSomePendingActivities"
++ ]
++}
\ No newline at end of file
diff --git a/tests/test_todo_parser.py b/tests/test_todo_parser.py
index 0753ab1..023c3de 100644
--- a/tests/test_todo_parser.py
+++ b/tests/test_todo_parser.py
@@ -33,6 +33,9 @@ class NewIssueTests(unittest.TestCase):
     def test_java_issues(self):
         self.assertEqual(count_issues_for_file_type(self.raw_issues, 'java'), 2)
 
+    def test_json5_issues(self):
+        self.assertEqual(count_issues_for_file_type(self.raw_issues, 'json5'), 1)
+
     def test_ruby_issues(self):
         # Includes 2 tests for Crystal.
         self.assertEqual(count_issues_for_file_type(self.raw_issues, 'ruby'), 5)