diff --git a/CMakeLists.txt b/CMakeLists.txt
index d4cfdb40..4d580df0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,10 +27,12 @@ IF(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
     set(HIDAPI_SRC ${PSMOVEAPI_SOURCE_DIR}/hidapi/mac/hid.c)
 ELSE(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
     find_package(PkgConfig REQUIRED)
+    find_package(Threads REQUIRED)
 
     pkg_check_modules(LIBUSB REQUIRED libusb-1.0)
     include_directories(${LIBUSB_INCLUDE_DIRS})
     list(APPEND PSMOVE_REQUIRED_LIBS ${LIBUSB_LIBRARIES})
+    list(APPEND PSMOVE_REQUIRED_LIBS ${CMAKE_THREAD_LIBS_INIT})
 
     # Only needed when using hidraw version of hidapi
     #pkg_check_modules(UDEV REQUIRED libudev)
diff --git a/qt/psmoveqt.cpp b/qt/psmoveqt.cpp
index 4ee37051..0a0fa06d 100644
--- a/qt/psmoveqt.cpp
+++ b/qt/psmoveqt.cpp
@@ -84,7 +84,7 @@ PSMoveQt::count()
 }
 
 bool
-PSMoveQt::pair()
+PSMoveQt::pair() const
 {
     if (psmove_pair(_move)) {
         return true;
@@ -94,7 +94,7 @@ PSMoveQt::pair()
 }
 
 int
-PSMoveQt::connectionType()
+PSMoveQt::connectionType() const
 {
     switch (psmove_connection_type(_move)) {
         case Conn_USB:
@@ -115,7 +115,7 @@ PSMoveQt::registerQML()
 #endif
 
 bool
-PSMoveQt::enabled()
+PSMoveQt::enabled() const
 {
     return _timer.isActive();
 }
@@ -135,7 +135,7 @@ PSMoveQt::setEnabled(bool enabled)
 }
 
 int
-PSMoveQt::trigger()
+PSMoveQt::trigger() const
 {
     return _trigger;
 }
@@ -162,13 +162,13 @@ PSMoveQt::setIndex(int index)
 }
 
 QColor
-PSMoveQt::color()
+PSMoveQt::color() const
 {
     return _color;
 }
 
 void
-PSMoveQt::setColor(QColor color)
+PSMoveQt::setColor(const QColor& color)
 {
     if (_color != color) {
         _color = color;
@@ -180,7 +180,7 @@ PSMoveQt::setColor(QColor color)
 }
 
 int
-PSMoveQt::rumble()
+PSMoveQt::rumble() const
 {
     return _rumble;
 }
diff --git a/qt/psmoveqt.hpp b/qt/psmoveqt.hpp
index ec8c17e4..16fa93e6 100644
--- a/qt/psmoveqt.hpp
+++ b/qt/psmoveqt.hpp
@@ -54,7 +54,7 @@ class PSMoveQt : public QObject
 
     static int count();
 
-    bool pair();
+    bool pair() const;
 
     enum ButtonType {
         Triangle = Btn_TRIANGLE,
@@ -74,29 +74,29 @@ class PSMoveQt : public QObject
         Unknown = Conn_Unknown,
     };
 
-    int connectionType();
+    int connectionType() const;
 
 #ifdef QT_DECLARATIVE_LIB
     static void registerQML();
 #endif
 
-    bool enabled();
+    bool enabled() const;
     void setEnabled(bool enabled);
-    int trigger();
+    int trigger() const;
     void setTrigger(int trigger);
-    QColor color();
-    void setColor(QColor color);
-    int rumble();
+    QColor color() const;
+    void setColor(const QColor& color);
+    int rumble() const;
     void setRumble(int rumble);
 
-    int ax() { return _ax; }
-    int ay() { return _ay; }
-    int az() { return _az; }
-    int gx() { return _gx; }
-    int gy() { return _gy; }
-    int gz() { return _gz; }
+    int ax() const { return _ax; }
+    int ay() const { return _ay; }
+    int az() const { return _az; }
+    int gx() const { return _gx; }
+    int gy() const { return _gy; }
+    int gz() const { return _gz; }
 
-    int index() { return _index; }
+    int index() const { return _index; }
     void setIndex(int index);
 
     Q_PROPERTY(bool enabled READ enabled WRITE setEnabled NOTIFY enabledChanged)