diff --git a/app/models/application_model.rb b/app/models/application_model.rb
index 0218203ec..548c234de 100644
--- a/app/models/application_model.rb
+++ b/app/models/application_model.rb
@@ -442,7 +442,7 @@ returns
       # do lookup with == to handle case insensitive databases
       records = where(login: data[:login])
       records.each {|loop_record|
-        if loop_record.login.casecmp data[:login] == 0
+        if loop_record.login.casecmp(data[:login]) == 0
           loop_record.update_attributes(data)
           return loop_record
         end
@@ -455,7 +455,7 @@ returns
       # do lookup with == to handle case insensitive databases
       records = where(email: data[:email])
       records.each {|loop_record|
-        if loop_record.email.casecmp data[:email] == 0
+        if loop_record.email.casecmp(data[:email]) == 0
           loop_record.update_attributes(data)
           return loop_record
         end
@@ -468,7 +468,7 @@ returns
       # do lookup with == to handle case insensitive databases
       records = where(locale: data[:locale])
       records.each {|loop_record|
-        if loop_record.locale.casecmp data[:locale] == 0
+        if loop_record.locale.casecmp(data[:locale]) == 0
           loop_record.update_attributes(data)
           return loop_record
         end
diff --git a/lib/core_ext/string.rb b/lib/core_ext/string.rb
index 68f611e86..01e3e4f22 100644
--- a/lib/core_ext/string.rb
+++ b/lib/core_ext/string.rb
@@ -31,7 +31,7 @@ class String
 =end
 
   def to_filename
-    camel_cased_word = to_s
+    camel_cased_word = "#{self}" # rubocop:disable Style/UnneededInterpolation
     camel_cased_word.gsub(/::/, '/')
                     .gsub(/([A-Z]+)([A-Z][a-z])/, '\1_\2')
                     .gsub(/([a-z\d])([A-Z])/, '\1_\2')
@@ -48,7 +48,7 @@ class String
 =end
 
   def to_classname
-    camel_cased_word = to_s
+    camel_cased_word = "#{self}" # rubocop:disable Style/UnneededInterpolation
     camel_cased_word.gsub!(/\.rb$/, '')
     camel_cased_word.split('/').map(&:camelize).join('::')
   end
@@ -79,7 +79,7 @@ class String
 =end
 
   def html2text(string_only = false)
-    string = to_s
+    string = "#{self}" # rubocop:disable Style/UnneededInterpolation
 
     # in case of invalid encodeing, strip invalid chars
     # see also test/fixtures/mail21.box
@@ -210,7 +210,7 @@ class String
 =end
 
   def text2html
-    text = CGI.escapeHTML( self )
+    text = CGI.escapeHTML(self)
     text.gsub!(/\n/, '<br>')
     text.chomp
   end