diff --git a/src/spectator/core/filters.cr b/src/spectator/core/filters.cr
index 7873970a..6600a64f 100644
--- a/src/spectator/core/filters.cr
+++ b/src/spectator/core/filters.cr
@@ -2,11 +2,11 @@ require "./example"
 require "./location"
 
 module Spectator::Core
-  abstract struct Filter
+  abstract class Filter
     abstract def matches?(example : Example)
   end
 
-  struct ExampleFilter < Filter
+  class ExampleFilter < Filter
     def initialize(@substring : String)
     end
 
@@ -15,7 +15,7 @@ module Spectator::Core
     end
   end
 
-  struct LineFilter < Filter
+  class LineFilter < Filter
     def initialize(@line : Int32)
     end
 
@@ -24,7 +24,7 @@ module Spectator::Core
     end
   end
 
-  struct LocationFilter < Filter
+  class LocationFilter < Filter
     def initialize(@location : Location)
     end
 
@@ -33,7 +33,7 @@ module Spectator::Core
     end
   end
 
-  struct TagFilter < Filter
+  class TagFilter < Filter
     @tags = [] of {String, String?}
 
     def matches?(example : Example)
@@ -48,7 +48,16 @@ module Spectator::Core
     end
   end
 
-  struct CompoundFilter < Filter
+  class NegatedFilter < Filter
+    def initialize(@filter : Filter)
+    end
+
+    def matches?(example : Example)
+      !@filter.matches?(example)
+    end
+  end
+
+  class CompoundFilter < Filter
     def initialize(@filters : Array(Filter))
     end
 
diff --git a/src/spectator/core/runner.cr b/src/spectator/core/runner.cr
index 6c35898e..4b950010 100644
--- a/src/spectator/core/runner.cr
+++ b/src/spectator/core/runner.cr
@@ -5,6 +5,7 @@ require "./example"
 require "./example_group"
 require "./execution_result"
 require "./fail_reason"
+require "./filters"
 require "./sandbox"
 
 module Spectator::Core
@@ -60,14 +61,14 @@ module Spectator::Core
     end
 
     private def examples_to_run(group : ExampleGroup) : Array(Example)
-      examples = group.select(Example)
       if filter = @configuration.inclusion_filter
-        examples.select! { |example| filter.matches?(example) }
+        group.filter(filter)
       end
       if filter = @configuration.exclusion_filter
-        examples.reject! { |example| filter.matches?(example) }
+        filter = NegatedFilter.new(filter)
+        group.filter(filter)
       end
-      examples
+      group.select(Example)
     end
 
     private def run_example(example : Example) : ExecutionResult