diff --git a/lib/shoulda/matchers/active_model/validate_inclusion_of_matcher.rb b/lib/shoulda/matchers/active_model/validate_inclusion_of_matcher.rb
index 785bd504e..9395cb5bd 100644
--- a/lib/shoulda/matchers/active_model/validate_inclusion_of_matcher.rb
+++ b/lib/shoulda/matchers/active_model/validate_inclusion_of_matcher.rb
@@ -309,8 +309,8 @@ def in_array(array)
 
         def in_range(range)
           @range = range
-          @minimum = range.first
-          @maximum = range.max
+          @minimum = minimum_range_value
+          @maximum = maximum_range_value
           self
         end
 
@@ -400,6 +400,18 @@ def does_not_match?(subject)
 
         private
 
+        def minimum_range_value
+          @range.begin
+        end
+
+        def maximum_range_value
+          if @range.exclude_end?
+            @range.end ? (@range.end - 1) : nil
+          else
+            @range.end
+          end
+        end
+
         def matches_for_range?
           disallows_lower_value &&
             allows_minimum_value &&
@@ -441,27 +453,27 @@ def disallows_lower_value
         end
 
         def allows_minimum_value
-          allows_value_of(@minimum, @low_message)
+          @minimum.nil? || allows_value_of(@minimum, @low_message)
         end
 
         def disallows_minimum_value
-          disallows_value_of(@minimum, @low_message)
+          @minimum.nil? || disallows_value_of(@minimum, @low_message)
         end
 
         def allows_maximum_value
-          allows_value_of(@maximum, @high_message)
+          @maximum.nil? || allows_value_of(@maximum, @high_message)
         end
 
         def disallows_maximum_value
-          disallows_value_of(@maximum, @high_message)
+          @maximum.nil? || disallows_value_of(@maximum, @high_message)
         end
 
         def allows_higher_value
-          allows_value_of(@maximum + 1, @high_message)
+          @maximum.nil? || allows_value_of(@maximum + 1, @high_message)
         end
 
         def disallows_higher_value
-          disallows_value_of(@maximum + 1, @high_message)
+          @maximum.nil? || disallows_value_of(@maximum + 1, @high_message)
         end
 
         def allows_all_values_in_array?
diff --git a/lib/shoulda/matchers/util.rb b/lib/shoulda/matchers/util.rb
index 521446325..2fc78b737 100644
--- a/lib/shoulda/matchers/util.rb
+++ b/lib/shoulda/matchers/util.rb
@@ -66,7 +66,7 @@ def self.inspect_values(values)
       end
 
       def self.inspect_range(range)
-        "#{inspect_value(range.first)} to #{inspect_value(range.last)}"
+        "#{inspect_value(range.begin)} to #{inspect_value(range.end)}"
       end
 
       def self.inspect_hash(hash)
diff --git a/spec/unit/shoulda/matchers/active_model/validate_inclusion_of_matcher_spec.rb b/spec/unit/shoulda/matchers/active_model/validate_inclusion_of_matcher_spec.rb
index 512a610fa..52275d880 100644
--- a/spec/unit/shoulda/matchers/active_model/validate_inclusion_of_matcher_spec.rb
+++ b/spec/unit/shoulda/matchers/active_model/validate_inclusion_of_matcher_spec.rb
@@ -572,6 +572,22 @@ def configure_validation_matcher(matcher)
       expect_to_match_on_values(builder, possible_values)
     end
 
+    it 'matches given a beginless range that covers the possible values' do
+      builder = build_object_allowing(possible_values)
+      expect_to_match_on_values(
+        builder,
+        Range.new(nil, possible_values.last),
+      )
+    end
+
+    it 'matches given a endless range that covers the possible values' do
+      builder = build_object_allowing(possible_values)
+      expect_to_match_on_values(
+        builder,
+        Range.new(possible_values.first, nil),
+      )
+    end
+
     it 'does not match given a range whose start value falls outside valid range' do
       builder = build_object_allowing(possible_values)
       expect_not_to_match_on_values(