diff --git a/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/query/execute/QueryExecutionOptions.java b/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/query/execute/QueryExecutionOptions.java
index ffc081b0b72ef2681222fb2e4cfc8d58f64a81a6..7cb1d060109e452a679ecad1fa95078be054ae9f 100644
--- a/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/query/execute/QueryExecutionOptions.java
+++ b/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/query/execute/QueryExecutionOptions.java
@@ -52,7 +52,7 @@ public class QueryExecutionOptions implements Serializable
     @Override
     public String toString()
     {
-        return getClass().getSimpleName() + ": parameters=" + parameters;
+        return getClass().getSimpleName() + ": parameterKeys=" + parameters.keySet();
     }
 
 }
diff --git a/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/query/execute/SqlExecutionOptions.java b/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/query/execute/SqlExecutionOptions.java
index 194b346df97a7d5d69632a0eaa16e5a13523e7bb..1d1071d40771e66e64564a74144038f44c012c48 100644
--- a/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/query/execute/SqlExecutionOptions.java
+++ b/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/query/execute/SqlExecutionOptions.java
@@ -66,7 +66,7 @@ public class SqlExecutionOptions implements Serializable
     @Override
     public String toString()
     {
-        return getClass().getSimpleName() + ": databaseId=" + databaseId + ", parameters=" + parameters;
+        return getClass().getSimpleName() + ": databaseId=" + databaseId + ", parameterKeys=" + parameters.keySet();
     }
 
 }