diff --git a/django/core/template/__init__.py b/django/core/template/__init__.py
index 5a755fd15f..8144e651a1 100644
--- a/django/core/template/__init__.py
+++ b/django/core/template/__init__.py
@@ -78,7 +78,7 @@ ALLOWED_VARIABLE_CHARS = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01
 
 # what to report as the origin for templates that come from non-loader sources
 # (e.g. strings)
-UNKNOWN_SOURCE="<unknown source>"
+UNKNOWN_SOURCE="&lt;unknown source&gt;"
 
 # match a variable or block tag and capture the entire tag, including start/end delimiters
 tag_re = re.compile('(%s.*?%s|%s.*?%s)' % (re.escape(BLOCK_TAG_START), re.escape(BLOCK_TAG_END),