diff --git a/CHANGES b/CHANGES
index 6ad9ed9..e691f23 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,11 @@ Corrections:
 	detailled information about the error with recvmsg(). Error return of
 	this function is now logged as Info instead of Warn.
 
+	Tests of the correction of the "IP_ADD_SOURCE_MEMBERSHIP but not struct
+	ip_mreq_source" issue left an #undef in xiosysincludes.h that disabled
+	the ip-add-source-membership option.
+	Thanks to Benjamin Poirier for sending a patch.
+
 Coding:
 	New Environment variable SOCAT_TRANSFER_WAIT that Socat sleep before
 	starting the data transfer loop. Useful, e.g., to accumulate multiple
diff --git a/xiosysincludes.h b/xiosysincludes.h
index 71eba0f..f509c0a 100644
--- a/xiosysincludes.h
+++ b/xiosysincludes.h
@@ -9,7 +9,5 @@
 #include "xioconfig.h"	/* what features are enabled */
 
 #include "sysincludes.h"
-//#undef IP_ADD_SOURCE_MEMBERSHIP
-#undef HAVE_STRUCT_IP_MREQ_SOURCE
 
 #endif /* !defined(__xiosysincludes_h_included) */