diff --git a/src/resources/devtools/forbidden-signatures.txt b/src/resources/devtools/forbidden-signatures.txt
index d63805ac02..a95abb7174 100644
--- a/src/resources/devtools/forbidden-signatures.txt
+++ b/src/resources/devtools/forbidden-signatures.txt
@@ -21,10 +21,10 @@
 @defaultMessage POI forbidden APIs
 
 # Locale related interfaces which we want to avoid to not have code which depends on the locale of the current machine
-java.util.Locale#getDefault() @ Do not use methods that depend on the current Local, either use Locale.ROOT or let the user define the local, see class LocaleUtil for details
-java.util.Locale#setDefault(java.util.Locale) @ Do not use methods that depend on the current Local, either use Locale.ROOT or let the user define the local, see class LocaleUtil for details
-java.util.TimeZone#getDefault() @ Do not use methods that depend on the current Local, either use Locale.ROOT or let the user define the local, see class LocaleUtil for details
-java.util.Date#toString() @ Do not use methods that depend on the current Local, either use Locale.ROOT or let the user define the local, see class LocaleUtil for details
+java.util.Locale#getDefault() @ Do not use methods that depend on the current Locale, either use Locale.ROOT or let the user define the locale, see class LocaleUtil for details
+java.util.Locale#setDefault(java.util.Locale) @ Do not use methods that depend on the current Locale, either use Locale.ROOT or let the user define the locale, see class LocaleUtil for details
+java.util.TimeZone#getDefault() @ Do not use methods that depend on the current Locale, either use Locale.ROOT or let the user define the locale, see class LocaleUtil for details
+java.util.Date#toString() @ Do not use methods that depend on the current Locale, either use Locale.ROOT or let the user define the locale, see class LocaleUtil for details
 
 java.text.DecimalFormatSymbols#<init>() @ use DecimalFormatSymbols.getInstance()
 java.text.DecimalFormatSymbols#<init>(java.util.Locale) @ use DecimalFormatSymbols.getInstance()
@@ -100,6 +100,13 @@ java.util.concurrent.Executors#privilegedThreadFactory()
 java.lang.Character#codePointBefore(char[],int) @ Implicit start offset is error-prone when the char[] is a buffer and the first chars are random chars
 java.lang.Character#codePointAt(char[],int) @ Implicit end offset is error-prone when the char[] is a buffer and the last chars are random chars
 
+@defaultMessage specify a locale when using toUpperCase / to LowerCase
+
+#java.lang.Character#toLowerCase(char)
+#java.lang.Character#toUpperCase(char)
+java.lang.String#toLowerCase()
+java.lang.String#toUpperCase()
+
 @defaultMessage Only use wait / notify when really needed try to use concurrency primitives, latches or callbacks instead.
 java.lang.Object#wait()
 java.lang.Object#wait(long)