diff --git a/homeassistant/helpers/selector.py b/homeassistant/helpers/selector.py
index 8b113cf1bba..34c9446c3de 100644
--- a/homeassistant/helpers/selector.py
+++ b/homeassistant/helpers/selector.py
@@ -855,7 +855,7 @@ class DurationSelector(Selector[DurationSelectorConfig]):
             vol.Optional("enable_day"): cv.boolean,
             # Enable millisecond field in frontend.
             vol.Optional("enable_millisecond"): cv.boolean,
-            # Allow negative durations. Will default to False in HA Core 2025.6.0.
+            # Allow negative durations.
             vol.Optional("allow_negative"): cv.boolean,
         }
     )
@@ -866,7 +866,7 @@ class DurationSelector(Selector[DurationSelectorConfig]):
 
     def __call__(self, data: Any) -> dict[str, float]:
         """Validate the passed selection."""
-        if self.config.get("allow_negative", True):
+        if self.config.get("allow_negative", False):
             cv.time_period_dict(data)
         else:
             cv.positive_time_period_dict(data)
diff --git a/tests/helpers/test_selector.py b/tests/helpers/test_selector.py
index fba9018b698..2f803e4da1e 100644
--- a/tests/helpers/test_selector.py
+++ b/tests/helpers/test_selector.py
@@ -1308,17 +1308,17 @@ def test_attribute_selector_schema(
                 {"days": 10},  # Days is allowed also if `enable_day` is not set
                 {"milliseconds": 500},
             ),
-            (None, {}),
+            (None, {}, {"seconds": -1}),
         ),
         (
             {"enable_day": True, "enable_millisecond": True},
             ({"seconds": 10}, {"days": 10}, {"milliseconds": 500}),
-            (None, {}),
+            (None, {}, {"seconds": -1}),
         ),
         (
-            {"allow_negative": False},
-            ({"seconds": 10}, {"days": 10}),
-            (None, {}, {"seconds": -1}),
+            {"allow_negative": True},
+            ({"seconds": 10}, {"seconds": -1}),
+            (None, {}),
         ),
     ],
 )