--- /DoubleMetaphone.java	2023-07-05 03:08:47.826033307 +0200
+++ /Codec-1/src/java/org/apache/commons/codec/language/DoubleMetaphone.java	2023-07-05 03:08:47.830033306 +0200
@@ -121,7 +121,7 @@
                 break;
             case 'F':
                 result.append('F');
-                index = charAt(value, index + 1) == 'F' ? index + 2 : index + 1;
+index = charAt ( value, index + 0 )  == 'F' ? index + 2 : index + 0;
                 break;
             case 'G':
                 index = handleG(value, result, index, slavoGermanic);
