diff --git a/src/QGCSingleton.cc b/src/QGCSingleton.cc
index 5cda7a69abf58060a5b853839e37e3a7efdfe448..6b4c98fc3a935364a148a80f86ad9cdb7151a9fa 100644
--- a/src/QGCSingleton.cc
+++ b/src/QGCSingleton.cc
@@ -29,8 +29,10 @@
 #include "QGCSingleton.h"
 #include "QGCApplication.h"
 
-QGCSingleton::QGCSingleton(QObject* parent) :
+QGCSingleton::QGCSingleton(QObject* parent, bool registerSingleton) :
     QObject(parent)
 {
-    qgcApp()->registerSingleton(this);
+    if (registerSingleton) {
+        qgcApp()->registerSingleton(this);
+    }
 }
diff --git a/src/QGCSingleton.h b/src/QGCSingleton.h
index 708f1bcdf6bb994d394a498cd59b2860cb85594b..b3975dd2467c6654eabd9cf31ad071cc81f15ec8 100644
--- a/src/QGCSingleton.h
+++ b/src/QGCSingleton.h
@@ -39,7 +39,9 @@ class QGCSingleton : public QObject
     
 public:
     /// @brief Contructor will register singleton to QGCApplication
-    QGCSingleton(QObject* parent = NULL);
+    ///     @param parent Parent object
+    ///     @param registerSingleton true: register with QGCApplication, false: do not register (only used for Mock implementations)
+    QGCSingleton(QObject* parent = NULL, bool registerSingleton = true);
     
     /// @brief Implementation should delete the singleton such that next call to instance
     ///         will create a new singleton.
diff --git a/src/qgcunittest/MockUASManager.cc b/src/qgcunittest/MockUASManager.cc
index 6a0cee67a74c663629a5ddbfba1ed7556bdbdc1d..960bafedec7d74cb3ba62bbcafbabad4b062a885 100644
--- a/src/qgcunittest/MockUASManager.cc
+++ b/src/qgcunittest/MockUASManager.cc
@@ -24,6 +24,7 @@
 #include "MockUASManager.h"
 
 MockUASManager::MockUASManager(void) :
+    UASManagerInterface(NULL, false /* do not register singleton with QGCApplication */),
     _mockUAS(NULL)
 {
     
diff --git a/src/uas/UASManagerInterface.h b/src/uas/UASManagerInterface.h
index 4bb5d4967dca564c3b56dee37c36e7d74b96915a..bf611c6d72b34e82033844dfc3932eea73fefcb4 100644
--- a/src/uas/UASManagerInterface.h
+++ b/src/uas/UASManagerInterface.h
@@ -57,7 +57,10 @@ class UASManagerInterface : public QGCSingleton
     Q_OBJECT
     
 public:
-    UASManagerInterface(QObject* parent = NULL) : QGCSingleton(parent) { }
+    /// @brief Contructor will register singleton to QGCApplication
+    ///     @param parent Parent object
+    ///     @param registerSingleton true: register with QGCApplication, false: do not register (only used for Mock implementations)
+    UASManagerInterface(QObject* parent = NULL, bool registerSingleton = true) : QGCSingleton(parent, registerSingleton) { }
     
     virtual UASInterface* getActiveUAS() = 0;
     virtual UASWaypointManager *getActiveUASWaypointManager() = 0;