diff --git a/tools/wptrunner/wptrunner/stability.py b/tools/wptrunner/wptrunner/stability.py
index e684bf68076752..db388bbca0a2be 100644
--- a/tools/wptrunner/wptrunner/stability.py
+++ b/tools/wptrunner/wptrunner/stability.py
@@ -115,8 +115,9 @@ def find_slow_status(test):
     """Check if a single test almost times out.
 
     We are interested in tests that almost time out (i.e. likely to be flaky).
-    Therefore, timeout statuses are ignored, including (EXTERNAL-)TIMEOUT &
-    CRASH (tests that time out may be marked as CRASH if crashes are detected).
+    Therefore, timeout statuses are ignored, including (EXTERNAL-)TIMEOUT.
+    CRASH & ERROR are also ignored because the they override TIMEOUT; a test
+    that both crashes and times out is marked as CRASH, so it won't be flaky.
 
     Returns:
         A result status produced by a run that almost times out; None, if no
@@ -125,7 +126,7 @@ def find_slow_status(test):
     if "timeout" not in test:
         return None
     threshold = test["timeout"] * FLAKY_THRESHOLD
-    for status in ['PASS', 'FAIL', 'OK', 'ERROR']:
+    for status in ['PASS', 'FAIL', 'OK']:
         if (status in test["longest_duration"] and
             test["longest_duration"][status] > threshold):
             return status
diff --git a/tools/wptrunner/wptrunner/tests/test_stability.py b/tools/wptrunner/wptrunner/tests/test_stability.py
index 5a051b6c899868..c3c89f2f192e9f 100644
--- a/tools/wptrunner/wptrunner/tests/test_stability.py
+++ b/tools/wptrunner/wptrunner/tests/test_stability.py
@@ -20,6 +20,9 @@ def test_find_slow_status():
     assert stability.find_slow_status({
         "longest_duration": {"CRASH": 10},
         "timeout": 10}) is None
+    assert stability.find_slow_status({
+        "longest_duration": {"ERROR": 10},
+        "timeout": 10}) is None
     assert stability.find_slow_status({
         "longest_duration": {"PASS": 1},
         "timeout": 10}) is None