diff --git a/telescope/utils.py b/telescope/utils.py
index 458f987f..103e780f 100644
--- a/telescope/utils.py
+++ b/telescope/utils.py
@@ -281,7 +281,10 @@ def extract_json(path, data):
                 istep = int(step)
             except ValueError:
                 raise ValueError(str(ke))  # Original error with step as string
-            data = data[istep]
+            try:
+                data = data[istep]
+            except IndexError:
+                raise ValueError(str(ke))  # Original error with step as string
     return data
 
 
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 138cb15b..38c082a7 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -61,9 +61,17 @@ def test_extract_json():
     assert extract_json(".pings.0", data) == 314
     assert extract_json(".min_timestamp", data) == "2020-09-24T10:29:44.925"
 
-    with pytest.raises(ValueError):
+    with pytest.raises(ValueError) as exc_info:
         extract_json(".pings.a", data)
+    assert str(exc_info.value) == "list indices must be integers or slices, not str"
+
+    with pytest.raises(ValueError) as exc_info:
         extract_json(".field", "An error returned by check")
+    assert str(exc_info.value) == "string indices must be integers"
+
+    with pytest.raises(ValueError) as exc_info:
+        extract_json(".percentiles.75.value", {"percentiles": "No results"})
+    assert str(exc_info.value) == "string indices must be integers"
 
 
 async def test_bugzilla_fetch_fallsback_to_empty_list(mock_aioresponses, config):