diff --git a/source/Platform/Unix/X11Mouse.cpp b/source/Platform/Unix/X11Mouse.cpp
index 850eec0..9ef045a 100644
--- a/source/Platform/Unix/X11Mouse.cpp
+++ b/source/Platform/Unix/X11Mouse.cpp
@@ -39,6 +39,12 @@ Vector2f X11Mouse::getAbsPosition() const
 
 bool X11Mouse::isButtonDown(Mouse::Button button) const
 {
+	// Only signal that a button is down
+	// if we have focus on a window.
+	if (!m_win) {
+		return false;
+	}
+
 	// TODO: Button1 and 2 is defined in x11 and
 	// therefore clashes with Mouse::Button::Button1 and 2.
 	switch(button) {