diff --git a/lib/gettext/tools/parser/erb.rb b/lib/gettext/tools/parser/erb.rb
index 80c88a3b..c931a7b6 100644
--- a/lib/gettext/tools/parser/erb.rb
+++ b/lib/gettext/tools/parser/erb.rb
@@ -70,7 +70,7 @@ def parse
       else
         erb = ERB.new(content, nil, "-")
       end
-      src = erb.src
+      src = +erb.src
 
       # Force the src encoding back to the encoding in magic comment
       # or original content.