diff --git a/rtgui/adjuster.cc b/rtgui/adjuster.cc
index f73dd8a..a7a069c 100644
--- a/rtgui/adjuster.cc
+++ b/rtgui/adjuster.cc
@@ -17,7 +17,7 @@
  *  along with RawTherapee.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include "adjuster.h"
-#include <sigc++/class_slot.h>
+#include <sigc++/slot.h>
 #include <cmath>
 #include "multilangmgr.h"
 #include "../rtengine/rtengine.h"
diff --git a/rtgui/preferences.cc b/rtgui/preferences.cc
index 134c0d7..8ce1808 100644
--- a/rtgui/preferences.cc
+++ b/rtgui/preferences.cc
@@ -16,7 +16,7 @@
  *  You should have received a copy of the GNU General Public License
  *  along with RawTherapee.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include <sigc++/class_slot.h>
+#include <sigc++/slot.h>
 #include "preferences.h"
 #include "multilangmgr.h"
 #include "splash.h"
diff --git a/rtgui/thresholdadjuster.cc b/rtgui/thresholdadjuster.cc
index 6b41329..19cde25 100644
--- a/rtgui/thresholdadjuster.cc
+++ b/rtgui/thresholdadjuster.cc
@@ -17,7 +17,7 @@
  *  along with RawTherapee.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include "thresholdadjuster.h"
-#include <sigc++/class_slot.h>
+#include <sigc++/slot.h>
 #include <cmath>
 #include "multilangmgr.h"
 #include "../rtengine/rtengine.h"
diff --git a/rtgui/tonecurve.cc b/rtgui/tonecurve.cc
index 2e439e1..5f14200 100644
--- a/rtgui/tonecurve.cc
+++ b/rtgui/tonecurve.cc
@@ -18,7 +18,7 @@
  */
 #include "tonecurve.h"
 #include "adjuster.h"
-#include <sigc++/class_slot.h>
+#include <sigc++/slot.h>
 #include <iomanip>
 #include "ppversion.h"
 #include "edit.h"