diff --git a/UnitTests/HttpInterface/arangodb.rb b/UnitTests/HttpInterface/arangodb.rb
index 9eb1532903..f54d51c41f 100644
--- a/UnitTests/HttpInterface/arangodb.rb
+++ b/UnitTests/HttpInterface/arangodb.rb
@@ -67,8 +67,9 @@ class ArangoDB
   # expect json as output/response format
   format :json
 
-  # set timeout to 120 seconds
-  default_timeout 120 
+  # set timeout to 300 seconds - so we will see timeouts in the cluster with ther
+  # respective error messages from the coordinator.
+  default_timeout 300 
 
   # do not verify SSL
   default_options[:verify] = false
diff --git a/arangod/VocBase/transaction.cpp b/arangod/VocBase/transaction.cpp
index 2ec5300bac..4bb2a66993 100644
--- a/arangod/VocBase/transaction.cpp
+++ b/arangod/VocBase/transaction.cpp
@@ -398,14 +398,14 @@ static int LockCollection (TRI_transaction_collection_t* trxCollection,
             nestingLevel,
             "read-locking collection %llu",
             (unsigned long long) trxCollection->_cid);
-    res = document->beginReadTimed(trx->_timeout, TRI_TRANSACTION_DEFAULT_SLEEP_DURATION);
+    res = document->beginReadTimed(trx->_timeout, TRI_TRANSACTION_DEFAULT_SLEEP_DURATION * 3);
   }
   else {
     LOG_TRX(trx,
             nestingLevel,
             "write-locking collection %llu",
             (unsigned long long) trxCollection->_cid);
-    res = document->beginWriteTimed(trx->_timeout, TRI_TRANSACTION_DEFAULT_SLEEP_DURATION * 50);
+    res = document->beginWriteTimed(trx->_timeout, TRI_TRANSACTION_DEFAULT_SLEEP_DURATION * 3);
   }
 
   if (res == TRI_ERROR_NO_ERROR) {
diff --git a/js/server/modules/org/arangodb/aql.js b/js/server/modules/org/arangodb/aql.js
index 3c235dd86c..f46eefdb4a 100644
--- a/js/server/modules/org/arangodb/aql.js
+++ b/js/server/modules/org/arangodb/aql.js
@@ -4619,6 +4619,12 @@ function AQL_TEST_MODIFY (test, what) {
     delete what.f; 
     what.g = "foo";
   }
+  else if (test === 'DEADLOCK') {
+    var err = new ArangoError();
+    err.errorNum = INTERNAL.errors.ERROR_DEADLOCK.code;
+    err.errorMessage = INTERNAL.errors.ERROR_DEADLOCK.message;
+    throw err;
+  }
   return what; 
 }