diff --git a/OpenChange/GNUmakefile b/OpenChange/GNUmakefile
index ee42a914f..af5db8ec5 100644
--- a/OpenChange/GNUmakefile
+++ b/OpenChange/GNUmakefile
@@ -39,6 +39,7 @@ $(SOGOBACKEND)_OBJC_FILES += \
 	\
 	SOGoAppointmentObject+MAPIStore.m \
 	SOGoGCSFolder+MAPIStore.m \
+	SOGoContentObject+MAPIStore.m \
 	SOGoContactGCSEntry+MAPIStore.m \
 	SOGoTaskObject+MAPIStore.m \
 	\