diff --git a/SoObjects/SOGo/GNUmakefile b/SoObjects/SOGo/GNUmakefile
index a66052ce1..ab9a8e4b0 100644
--- a/SoObjects/SOGo/GNUmakefile
+++ b/SoObjects/SOGo/GNUmakefile
@@ -32,6 +32,7 @@ libSOGo_HEADER_FILES = \
 	SOGoLRUCache.h			\
 	NSObject+AptComparison.h	\
 	WOContext+Agenor.h		\
+	NSObject+Owner.h		\
 	NSString+URL.h			\
 	NSDictionary+URL.h		\
 	NSCalendarDate+SOGo.h		\
@@ -51,6 +52,7 @@ libSOGo_OBJC_FILES = \
 	SOGoLRUCache.m			\
 	AgenorUserManager.m		\
 	NSObject+AptComparison.m	\
+	NSObject+Owner.m		\
 	WOContext+Agenor.m		\
 	AgenorUserDefaults.m		\
 	NSDictionary+URL.m		\