diff --git a/activemodel/lib/active_model/validations/uniqueness.rb b/activemodel/lib/active_model/validations/uniqueness.rb
index 2b47c6bc09..68cd6169e5 100644
--- a/activemodel/lib/active_model/validations/uniqueness.rb
+++ b/activemodel/lib/active_model/validations/uniqueness.rb
@@ -25,7 +25,7 @@ module ActiveModel
       # Configuration options:
       # * <tt>:message</tt> - Specifies a custom error message (default is: "has already been taken")
       # * <tt>:scope</tt> - One or more columns by which to limit the scope of the uniqueness constraint.
-      # * <tt>:case_sensitive</tt> - Looks for an exact match.  Ignored by non-text columns (+false+ by default).
+      # * <tt>:case_sensitive</tt> - Looks for an exact match.  Ignored by non-text columns (+true+ by default).
       # * <tt>:allow_nil</tt> - If set to +true+, skips this validation if the attribute is +nil+ (default is: +false+)
       # * <tt>:allow_blank</tt> - If set to +true+, skips this validation if the attribute is blank (default is: +false+)
       # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should
@@ -101,4 +101,4 @@ module ActiveModel
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index e7a9676394..b8b695e529 100644
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -597,7 +597,7 @@ module ActiveRecord
       # Configuration options:
       # * <tt>:message</tt> - Specifies a custom error message (default is: "has already been taken").
       # * <tt>:scope</tt> - One or more columns by which to limit the scope of the uniqueness constraint.
-      # * <tt>:case_sensitive</tt> - Looks for an exact match.  Ignored by non-text columns (+false+ by default).
+      # * <tt>:case_sensitive</tt> - Looks for an exact match. Ignored by non-text columns (+true+ by default).
       # * <tt>:allow_nil</tt> - If set to true, skips this validation if the attribute is +nil+ (default is +false+).
       # * <tt>:allow_blank</tt> - If set to true, skips this validation if the attribute is blank (default is +false+).
       # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should