diff --git a/lib/skywatch/brief/analysis/adverse_filter.rb b/lib/skywatch/brief/analysis/adverse_filter.rb
index b83d3ef..6955e32 100644
--- a/lib/skywatch/brief/analysis/adverse_filter.rb
+++ b/lib/skywatch/brief/analysis/adverse_filter.rb
@@ -9,6 +9,8 @@ def self.covers?(product, lat, lon)
           return false if polygon.nil?
 
           polygon.contains?(Skywatch::Shared::Geometry.point(lat, lon))
+        rescue RGeo::Error::InvalidGeometry
+          false
         end
 
         def self.within(items, lat:, lon:, radius_nm:)
diff --git a/lib/skywatch/nimbus/models/outlook.rb b/lib/skywatch/nimbus/models/outlook.rb
index 2b6324b..911189d 100644
--- a/lib/skywatch/nimbus/models/outlook.rb
+++ b/lib/skywatch/nimbus/models/outlook.rb
@@ -70,6 +70,8 @@ def covers?(lat:, lon:)
           return false if geometry.nil?
 
           geometry.contains?(FACTORY.point(lon, lat))
+        rescue RGeo::Error::InvalidGeometry
+          false
         end
 
         def to_h # rubocop:disable Metrics/MethodLength
diff --git a/spec/brief/analysis/adverse_filter_spec.rb b/spec/brief/analysis/adverse_filter_spec.rb
index 2fe89f3..90be894 100644
--- a/spec/brief/analysis/adverse_filter_spec.rb
+++ b/spec/brief/analysis/adverse_filter_spec.rb
@@ -27,6 +27,19 @@
       degenerate = Skywatch::Briefer::Models::Sigmet.new(coords: [])
       expect(described_class.covers?(degenerate, 40.875, -74.282)).to be false
     end
+
+    it 'returns false when the polygon is self-intersecting (RGeo InvalidGeometry)' do
+      # Bowtie ring: edges cross — RGeo raises Self-intersection on contains?
+      bowtie = Skywatch::Briefer::Models::Sigmet.new(coords: [
+                                                       Skywatch::Shared::Position.new(lat: 40.0, lon: -74.0),
+                                                       Skywatch::Shared::Position.new(lat: 41.0, lon: -73.0),
+                                                       Skywatch::Shared::Position.new(lat: 40.0, lon: -73.0),
+                                                       Skywatch::Shared::Position.new(lat: 41.0, lon: -74.0),
+                                                       Skywatch::Shared::Position.new(lat: 40.0, lon: -74.0)
+                                                     ])
+      expect { described_class.covers?(bowtie, 40.5, -73.5) }.not_to raise_error
+      expect(described_class.covers?(bowtie, 40.5, -73.5)).to be false
+    end
   end
 
   describe '.within' do
diff --git a/spec/nimbus/models/outlook_spec.rb b/spec/nimbus/models/outlook_spec.rb
index eb103a3..5ab703c 100644
--- a/spec/nimbus/models/outlook_spec.rb
+++ b/spec/nimbus/models/outlook_spec.rb
@@ -93,6 +93,20 @@
       expect(mrgl.covers?(lat: 41.4, lon: -74.9)).to be(true)
       expect(slgt.covers?(lat: 41.4, lon: -74.9)).to be(false)
     end
+
+    it 'returns false when the geometry is self-intersecting (RGeo InvalidGeometry)' do
+      factory = described_class::FACTORY
+      bowtie_ring = factory.linear_ring([
+                                          factory.point(-74.0, 40.0),
+                                          factory.point(-73.0, 41.0),
+                                          factory.point(-73.0, 40.0),
+                                          factory.point(-74.0, 41.0),
+                                          factory.point(-74.0, 40.0)
+                                        ])
+      bad = described_class.new(**attrs, geometry: factory.polygon(bowtie_ring))
+      expect { bad.covers?(lat: 40.5, lon: -73.5) }.not_to raise_error
+      expect(bad.covers?(lat: 40.5, lon: -73.5)).to be(false)
+    end
   end
 
   describe '#to_h' do