diff --git a/server/Client.cc b/server/Client.cc
index 622766c..b71c1cb 100644
--- a/server/Client.cc
+++ b/server/Client.cc
@@ -1184,8 +1184,14 @@
 
     Snapper* snapper = it->getSnapper();
 
+    RefHolder ref_holder(*it);
+
+    lock.unlock();
+
     snapper->calculateUsedSpace();
 
+    lock.lock();
+
     DBus::MessageMethodReturn reply(msg);
 
     conn.send(reply);
@@ -1513,8 +1519,14 @@
 
     Snapper* snapper = it->getSnapper();
 
+    RefHolder ref_holder(*it);
+
+    lock.unlock();
+
     QuotaData quota_data = snapper->queryQuotaData();
 
+    lock.lock();
+
     DBus::MessageMethodReturn reply(msg);
 
     DBus::Hoho hoho(reply);