diff --git a/demo.py b/demo.py
index 07b27a2b..7ee47732 100755
--- a/demo.py
+++ b/demo.py
@@ -144,7 +144,7 @@ def __init__(self):
         # API call settings
         self.default_limit = 100
         self.start = 0
-        self.start_badge = 1  # Badge related calls start counting at 1
+        self.start_badge = 1  # Badge, challenge and goal calls start counting at 1
 
         # Activity settings
         self.activityfile = "test_data/*.gpx"  # Supported file types: .fit .gpx .tcx
@@ -4942,26 +4942,26 @@ def execute_api_call(api: Garmin, key: str) -> None:
             "get_active_goals": lambda: call_and_display(
                 api.get_goals,
                 status="active",
-                start=config.start,
+                start=config.start_badge,
                 limit=config.default_limit,
                 method_name="get_goals",
-                api_call_desc=f"api.get_goals(status='active', start={config.start}, limit={config.default_limit})",
+                api_call_desc=f"api.get_goals(status='active', start={config.start_badge},limit={config.default_limit})",
             ),
             "get_future_goals": lambda: call_and_display(
                 api.get_goals,
                 status="future",
-                start=config.start,
+                start=config.start_badge,
                 limit=config.default_limit,
                 method_name="get_goals",
-                api_call_desc=f"api.get_goals(status='future', start={config.start}, limit={config.default_limit})",
+                api_call_desc=f"api.get_goals(status='future', start={config.start_badge},limit={config.default_limit})",
             ),
             "get_past_goals": lambda: call_and_display(
                 api.get_goals,
                 status="past",
-                start=config.start,
+                start=config.start_badge,
                 limit=config.default_limit,
                 method_name="get_goals",
-                api_call_desc=f"api.get_goals(status='past', start={config.start}, limit={config.default_limit})",
+                api_call_desc=f"api.get_goals(status='past', start={config.start_badge},limit={config.default_limit})",
             ),
             "get_badge_challenges": lambda: call_and_display(
                 api.get_badge_challenges,
diff --git a/garminconnect/__init__.py b/garminconnect/__init__.py
index b5b1c5a4..000eb537 100644
--- a/garminconnect/__init__.py
+++ b/garminconnect/__init__.py
@@ -2036,7 +2036,7 @@ def get_adhoc_challenges(self, start: int, limit: int) -> dict[str, Any]:
 
     def get_badge_challenges(self, start: int, limit: int) -> dict[str, Any]:
         """Return badge challenges for the current user."""
-        start = _validate_non_negative_integer(start, "start")
+        start = _validate_positive_integer(start, "start")
         limit = _validate_positive_integer(limit, "limit")
         url = self.garmin_connect_badge_challenges_url
         params = {"start": str(start), "limit": str(limit)}
@@ -2046,7 +2046,7 @@ def get_badge_challenges(self, start: int, limit: int) -> dict[str, Any]:
 
     def get_available_badge_challenges(self, start: int, limit: int) -> dict[str, Any]:
         """Return available badge challenges."""
-        start = _validate_non_negative_integer(start, "start")
+        start = _validate_positive_integer(start, "start")
         limit = _validate_positive_integer(limit, "limit")
         url = self.garmin_connect_available_badge_challenges_url
         params = {"start": str(start), "limit": str(limit)}
@@ -2058,7 +2058,7 @@ def get_non_completed_badge_challenges(
         self, start: int, limit: int
     ) -> dict[str, Any]:
         """Return badge non-completed challenges for current user."""
-        start = _validate_non_negative_integer(start, "start")
+        start = _validate_positive_integer(start, "start")
         limit = _validate_positive_integer(limit, "limit")
         url = self.garmin_connect_non_completed_badge_challenges_url
         params = {"start": str(start), "limit": str(limit)}
diff --git a/tests/test_garmin_unit.py b/tests/test_garmin_unit.py
index 1f27f1d7..6584f8ba 100644
--- a/tests/test_garmin_unit.py
+++ b/tests/test_garmin_unit.py
@@ -1902,6 +1902,21 @@ def test_get_goals_rejects_zero_start(self, garmin: garminconnect.Garmin):
         with pytest.raises(ValueError, match="positive integer"):
             garmin.get_goals(start=0)
 
+    @pytest.mark.parametrize(
+        "method",
+        [
+            "get_badge_challenges",
+            "get_available_badge_challenges",
+            "get_non_completed_badge_challenges",
+            "get_inprogress_virtual_challenges",
+        ],
+    )
+    def test_badge_challenges_reject_zero_start(
+        self, garmin: garminconnect.Garmin, method: str
+    ):
+        with pytest.raises(ValueError, match="positive integer"):
+            getattr(garmin, method)(0, 10)
+
     def test_get_goals_sends_sec_fetch_site_header(self, garmin: garminconnect.Garmin):
         """goal-service silently returns [] without this header (#431)."""
         with patch.object(garmin, "connectapi", return_value=[]) as mock: