diff --git a/AGENTS.md b/AGENTS.md
index 2616f78..87c46c9 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -32,4 +32,4 @@ This is a personal agenda web application built with Flask that tracks various e
 - Personal data directory (`personal-data/`) is excluded from git
 
 ## Notes
-- Trip stats new-country badges come from `agenda.stats.calculate_yearly_stats` via `year_stats.new_countries` (first-visit year); `templates/trip/stats.html` filters against `PREVIOUSLY_VISITED`.
+- Trip stats new-country badges come from `agenda.stats.calculate_yearly_stats` via `year_stats.new_countries` (first-visit year, excluding `PREVIOUSLY_VISITED`).
diff --git a/agenda/stats.py b/agenda/stats.py
index c74d94e..c3c8e4f 100644
--- a/agenda/stats.py
+++ b/agenda/stats.py
@@ -33,10 +33,13 @@ def conferences(trip: Trip, yearly_stats: Mapping[int, StrDict]) -> None:
         yearly_stats[c["start"].year]["conferences"] += 1
 
 
-def calculate_yearly_stats(trips: list[Trip]) -> dict[int, StrDict]:
+def calculate_yearly_stats(
+    trips: list[Trip], previously_visited: set[str] | None = None
+) -> dict[int, StrDict]:
     """Calculate total distance and distance by transport type grouped by year."""
     yearly_stats: defaultdict[int, StrDict] = defaultdict(dict)
     first_visit_year: dict[str, int] = {}
+    excluded_new: set[str] = previously_visited or set()
 
     for trip in trips:
         year = trip.start.year
@@ -72,7 +75,10 @@ def calculate_yearly_stats(trips: list[Trip]) -> dict[int, StrDict]:
                 continue
             yearly_stats[year].setdefault("countries", set())
             yearly_stats[year]["countries"].add(country)
-            if first_visit_year.get(country.alpha_2) == year:
+            if (
+                first_visit_year.get(country.alpha_2) == year
+                and country.alpha_2 not in excluded_new
+            ):
                 yearly_stats[year].setdefault("new_countries", set())
                 yearly_stats[year]["new_countries"].add(country)
 
diff --git a/templates/trip/stats.html b/templates/trip/stats.html
index 0e65005..e07766d 100644
--- a/templates/trip/stats.html
+++ b/templates/trip/stats.html
@@ -27,19 +27,13 @@
     <div>Trips in {{ year }}: {{ year_stats.count }}</div>
     <div>Conferences in {{ year }}: {{ year_stats.conferences }}</div>
     <div>{{ countries | count }} countries visited in {{ year }}:
-      {% set display_new_countries = [] %}
-      {% for c in new_countries %}
-        {% if c.alpha_2 not in previously_visited %}
-          {% set _ = display_new_countries.append(c) %}
-        {% endif %}
-      {% endfor %}
-      {% if display_new_countries %}
-        ({{ display_new_countries | count }} new)
+      {% if new_countries %}
+        ({{ new_countries | count }} new)
       {% endif %}
       {% for c in countries %}
         <span class="d-inline-block border border-2 p-1 m-1">
           {{ c.flag }} {{ c.name }} ({{ c.alpha_2 }})
-          {% if c in display_new_countries %}
+          {% if c in new_countries %}
             <span class="badge text-bg-info">new</span>
           {% endif %}
         </span>
diff --git a/tests/test_trip_stats.py b/tests/test_trip_stats.py
index 20ff7f5..37d04b6 100644
--- a/tests/test_trip_stats.py
+++ b/tests/test_trip_stats.py
@@ -27,3 +27,11 @@ def test_new_country_only_first_year() -> None:
     assert czechia in yearly_stats[2024]["new_countries"]
     assert czechia in yearly_stats[2026]["countries"]
     assert "new_countries" not in yearly_stats[2026]
+
+
+def test_new_country_respects_previously_visited() -> None:
+    """Ensure previously visited countries are excluded from new-country stats."""
+    trips = [make_trip(date(2024, 5, 1), "CZ")]
+
+    yearly_stats = calculate_yearly_stats(trips, {"CZ"})
+    assert "new_countries" not in yearly_stats[2024]
diff --git a/web_view.py b/web_view.py
index fa3c8ee..a61e257 100755
--- a/web_view.py
+++ b/web_view.py
@@ -461,7 +461,9 @@ def accommodation_list() -> str:
     items = travel.parse_yaml("accommodation", data_dir)
 
     # Create a dictionary to hold stats for each year
-    year_stats = defaultdict(lambda: {"total_nights": 0, "nights_abroad": 0})
+    year_stats: defaultdict[int, dict[str, int]] = defaultdict(
+        lambda: {"total_nights": 0, "nights_abroad": 0}
+    )
 
     # Calculate stats for each year
     for stay in items:
@@ -536,7 +538,7 @@ def calc_total_distance(trips: list[Trip]) -> float:
 
 def calc_total_co2_kg(trips: list[Trip]) -> float:
     """Total CO₂ for trips."""
-    return sum(item.total_co2_kg() for item in trips)
+    return sum(item.total_co2_kg() or 0.0 for item in trips)
 
 
 def sum_distances_by_transport_type(trips: list[Trip]) -> list[tuple[str, float]]:
@@ -806,7 +808,9 @@ def trip_stats() -> str:
 
     conferences = sum(len(item.conferences) for item in trip_list)
 
-    yearly_stats = agenda.stats.calculate_yearly_stats(trip_list)
+    yearly_stats = agenda.stats.calculate_yearly_stats(
+        trip_list, app.config.get("PREVIOUSLY_VISITED")
+    )
 
     return flask.render_template(
         "trip/stats.html",