diff --git a/app/models/cti/caller_id.rb b/app/models/cti/caller_id.rb
index 561712a19..dc09c98a1 100644
--- a/app/models/cti/caller_id.rb
+++ b/app/models/cti/caller_id.rb
@@ -178,6 +178,7 @@ returns
 
     def self.extract_numbers(text)
       # see specs for example
+      return [] if !text.is_a?(String)
       text.scan(/([\d|\s|\-|\(|\)]{6,26})/).map do |match|
         normalize_number(match[0])
       end