diff --git a/src/Makefile.am b/src/Makefile.am
index 1d4a80f7..05727b56 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -81,7 +81,7 @@ fluxbox_SOURCES = AtomHandler.hh ArrowButton.hh ArrowButton.cc \
 	RootTheme.hh RootTheme.cc \
 	FbRootWindow.hh FbRootWindow.cc \
 	Screen.cc Screen.hh \
-	Slit.cc Slit.hh SlitTheme.hh SlitClient.hh SlitClient.cc \
+	Slit.cc Slit.hh SlitTheme.hh SlitTheme.cc SlitClient.hh SlitClient.cc \
 	WinButton.hh WinButton.cc \
 	WinButtonTheme.hh WinButtonTheme.cc \
 	Window.cc Window.hh \