diff --git a/lib/shoulda/matchers/active_record/validate_uniqueness_of_matcher.rb b/lib/shoulda/matchers/active_record/validate_uniqueness_of_matcher.rb
index ad298b145..85cc81d2b 100644
--- a/lib/shoulda/matchers/active_record/validate_uniqueness_of_matcher.rb
+++ b/lib/shoulda/matchers/active_record/validate_uniqueness_of_matcher.rb
@@ -820,7 +820,7 @@ def next_scalar_value_for(scope, previous_value)
           elsif previous_value.respond_to?(:next)
             previous_value.next
           elsif previous_value.respond_to?(:to_datetime)
-            previous_value.to_datetime.next
+            previous_value.to_datetime.in(60).next
           elsif boolean_value?(previous_value)
             !previous_value
           else
diff --git a/spec/unit/shoulda/matchers/active_record/validate_uniqueness_of_matcher_spec.rb b/spec/unit/shoulda/matchers/active_record/validate_uniqueness_of_matcher_spec.rb
index f39ef9575..95725c93f 100644
--- a/spec/unit/shoulda/matchers/active_record/validate_uniqueness_of_matcher_spec.rb
+++ b/spec/unit/shoulda/matchers/active_record/validate_uniqueness_of_matcher_spec.rb
@@ -829,6 +829,11 @@
         column_type: :datetime
     end
 
+    context 'when one of the scoped attributes is a time column (using Time)' do
+      include_context 'it supports scoped attributes of a certain type',
+        column_type: :time
+    end
+
     context 'when one of the scoped attributes is a datetime column (using Time)' do
       include_context 'it supports scoped attributes of a certain type',
         column_type: :datetime,