diff --git a/detect_secrets/filters/heuristic.py b/detect_secrets/filters/heuristic.py
index 8f65edf4b..5b7dfb444 100644
--- a/detect_secrets/filters/heuristic.py
+++ b/detect_secrets/filters/heuristic.py
@@ -162,7 +162,9 @@ def is_prefixed_with_dollar_sign(secret: str) -> bool:
     # false negatives than `is_templated_secret` (e.g. secrets that actually start with a $).
     # This is best used with files that actually use this as a means of referencing variables.
     # TODO: More intelligent filetype handling?
-    return secret[0] == '$'
+    if len(secret) > 0 and secret[0] == '$':
+        return True
+    return False
 
 
 def is_indirect_reference(line: str) -> bool:
diff --git a/tests/filters/heuristic_filter_test.py b/tests/filters/heuristic_filter_test.py
index c408af4c7..6178d4d7c 100644
--- a/tests/filters/heuristic_filter_test.py
+++ b/tests/filters/heuristic_filter_test.py
@@ -124,6 +124,7 @@ def test_is_templated_secret(line, result):
 def test_is_prefixed_with_dollar_sign():
     assert filters.heuristic.is_prefixed_with_dollar_sign('$secret')
     assert not filters.heuristic.is_prefixed_with_dollar_sign('secret')
+    assert not filters.heuristic.is_prefixed_with_dollar_sign('')
 
 
 @pytest.mark.parametrize(