diff --git a/src/main/java/de/hsfulda/informatik/LdapSync.java b/src/main/java/de/hsfulda/informatik/LdapSync.java
index d46b44e..1188e40 100644
--- a/src/main/java/de/hsfulda/informatik/LdapSync.java
+++ b/src/main/java/de/hsfulda/informatik/LdapSync.java
@@ -25,7 +25,7 @@ import java.util.stream.Collectors;
  */
 public class LdapSync {
     private final Properties properties = new Properties();
-    private final static Pattern legacyPattern = Pattern.compile("^fd([a-z][a-z])?([0-9]*?)$");
+    private final static Pattern legacyPattern = Pattern.compile("^fd([a-z][a-z]?)?([0-9]*?)$");
     private final static Pattern newPattern = Pattern.compile("^fd([0-9][0-9][0-9][0-9][0-9][0-9][0-9])$");
     private final static Pattern newGuestPattern = Pattern.compile("^fdg([0-9][0-9][0-9][0-9][0-9])$");
     private Map<String, Integer> userDefinedMappings = Collections.emptyMap();
@@ -173,7 +173,9 @@ public class LdapSync {
 
             if (m.group(1) != null) {
                 a = m.group(1).charAt(0) - 96;
-                b = m.group(1).charAt(1) - 96;
+                if (m.group(1).length()>1) {
+                    b = m.group(1).charAt(1) - 96;
+                }
             }
 
             final int s = m.group(2).length();
diff --git a/src/test/java/de/hsfulda/informatik/LdapSyncTest.java b/src/test/java/de/hsfulda/informatik/LdapSyncTest.java
index 52ce44a..95ad068 100644
--- a/src/test/java/de/hsfulda/informatik/LdapSyncTest.java
+++ b/src/test/java/de/hsfulda/informatik/LdapSyncTest.java
@@ -30,6 +30,7 @@ public class LdapSyncTest {
         remoteEntries.add(searchResultEntry("dn=fDai1235,dc=remote,dc=de", "FDai1235", "Schuster", "Schuster"));
         remoteEntries.add(searchResultEntry("dn=fdaI1236,dc=remote,dc=de", "fdAI1236", "Bunsen", "Bunsen"));
         remoteEntries.add(searchResultEntry("dn=fDeT123,dc=remote,dc=de", "FDET123", "Bauer", "Bauer"));
+        remoteEntries.add(searchResultEntry("dn=fdw9424,dc=remote,dc=de", "fdw9424", "Hein", "Bloed"));
         remoteEntries.add(searchResultEntry("dn=fdXx9999,dc=remote,dc=de", "fdxX9999", "Schmidt", "Schmidt"));
         final AccountSource remote = new AccountSource("dc=remote,dc=de", remoteEntries);
 
@@ -55,7 +56,7 @@ public class LdapSyncTest {
         assertTrue(delSet.contains("fdai1237"));
         assertTrue(delSet.contains("fdai1238"));
 
-        assertEquals(addList.size(), 4);
+        assertEquals(5, addList.size());
 
         for (final Entry entry : addList) {
             assertTrue(entry.getDN().endsWith(",dc=local,dc=de"));
@@ -116,14 +117,17 @@ public class LdapSyncTest {
 
         mappings = LdapSync.parseUserDefinedMappings("fdg00244:300000244");
         assertEquals(300000244, (int) LdapSync.computeUid("fdg00244", mappings));
-        assertEquals(41000, (int) LdapSync.computeUid("fd1000", mappings));
-        assertEquals(49999, (int) LdapSync.computeUid("fd9999", mappings));
-        assertEquals(10141000, (int) LdapSync.computeUid("fdaa1000", mappings));
-        assertEquals(10149999, (int) LdapSync.computeUid("fdaa9999", mappings));
+        assertEquals(    41000, (int) LdapSync.computeUid("fd1000", mappings));
+        assertEquals(    49999, (int) LdapSync.computeUid("fd9999", mappings));
+        assertEquals( 10141000, (int) LdapSync.computeUid("fdaa1000", mappings));
         assertEquals(262641000, (int) LdapSync.computeUid("fdzz1000", mappings));
+        assertEquals( 10041000, (int) LdapSync.computeUid("fda1000", mappings));
+        assertEquals(260041000, (int) LdapSync.computeUid("fdz1000", mappings));
+        assertEquals( 10149999, (int) LdapSync.computeUid("fdaa9999", mappings));
         assertEquals(262649999, (int) LdapSync.computeUid("fdzz9999", mappings));
         assertEquals(300000000, (int) LdapSync.computeUid("fdg00000", mappings));
         assertEquals(300099999, (int) LdapSync.computeUid("fdg99999", mappings));
+        assertEquals(230049123, (int) LdapSync.computeUid("fdw9123", mappings));
 
         mappings = LdapSync.parseUserDefinedMappings("aaabbb");
         assertEquals(0, mappings.size());