diff --git a/openbis/source/java/ch/systemsx/cisd/openbis/generic/shared/basic/dto/SearchCriteria.java b/openbis/source/java/ch/systemsx/cisd/openbis/generic/shared/basic/dto/SearchCriteria.java
index 8e9d9c88b6c8df31a4d7e872b797688660cd0c61..043f8e0830ddc1a98a24491db08ab32c5aea3965 100644
--- a/openbis/source/java/ch/systemsx/cisd/openbis/generic/shared/basic/dto/SearchCriteria.java
+++ b/openbis/source/java/ch/systemsx/cisd/openbis/generic/shared/basic/dto/SearchCriteria.java
@@ -67,7 +67,7 @@ public class SearchCriteria implements IsSerializable
         final StringBuilder sb = new StringBuilder();
         for (final DataSetSearchCriterion element : getCriteria())
         {
-            if (sb.toString().equals("") == false)
+            if (sb.length() > 0)
             {
                 sb.append(" " + getConnection().name() + " ");
             }