diff --git a/GSMEncoding.st b/GSMEncoding.st
index 33da4fa..2bcac10 100644
--- a/GSMEncoding.st
+++ b/GSMEncoding.st
@@ -16,7 +16,7 @@
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 "
 
-Array extend [
+ArrayedCollection extend [
     decodeGSM7Bit [
         <category: '*OsmoGSM-coding'>
         ^ (OsmoGSM at: #GSMDecoding) decode: self.