diff --git a/ext2spice/ext2hier.c b/ext2spice/ext2hier.c
index fc010154..64578469 100644
--- a/ext2spice/ext2hier.c
+++ b/ext2spice/ext2hier.c
@@ -1619,7 +1619,7 @@ esMakePorts(hc, cdata)
 			nn = (EFNodeName *) HashGetValue(he);
 		    }
 
-		    if (!(nn->efnn_node->efnode_flags & EF_PORT))
+		    if (nn->efnn_node && !(nn->efnn_node->efnode_flags & EF_PORT))
 		    {
 			nn->efnn_node->efnode_flags |= EF_PORT;
 			nn->efnn_port = -1;	// Will be sorted later
diff --git a/ext2spice/ext2spice.c b/ext2spice/ext2spice.c
index 94b2eb53..221483a6 100644
--- a/ext2spice/ext2spice.c
+++ b/ext2spice/ext2spice.c
@@ -1668,7 +1668,7 @@ topVisit(def, doStub)
 	sname = (EFNodeName *) HashGetValue(he);
 	if (sname == NULL) continue;
 	snode = sname->efnn_node;
-	if (!(snode->efnode_flags & EF_PORT)) continue;
+	if ((!snode) || (!(snode->efnode_flags & EF_PORT))) continue;
 	for (nodeName = sname; nodeName != NULL; nodeName = nodeName->efnn_next)
 	{
 	    portorder = nodeName->efnn_port;
@@ -1729,7 +1729,7 @@ topVisit(def, doStub)
 		if (sname == NULL) continue;	/* Should not happen */
 		snode = sname->efnn_node;
 
-		if (!(snode->efnode_flags & EF_PORT)) continue;
+		if ((!snode) || (!(snode->efnode_flags & EF_PORT))) continue;
 
 		for (nodeName = sname; nodeName != NULL; nodeName = nodeName->efnn_next)
 		{
@@ -1787,7 +1787,7 @@ topVisit(def, doStub)
 	    if (sname == NULL) continue;
 	    snode = sname->efnn_node;
 
-	    if (snode->efnode_flags & EF_SUBS_PORT)
+	    if (snode && (snode->efnode_flags & EF_SUBS_PORT))
 	    {
 		if (snode->efnode_name->efnn_port < 0)
 		{
diff --git a/extflat/EFbuild.c b/extflat/EFbuild.c
index f4ba250b..33e43bc6 100644
--- a/extflat/EFbuild.c
+++ b/extflat/EFbuild.c
@@ -466,6 +466,8 @@ efBuildEquiv(def, nodeName1, nodeName2)
 	    if (efWarn)
 		efReadError("Merged nodes %s and %s\n", nodeName1, nodeName2);
 	    efNodeMerge(&nn1->efnn_node, &nn2->efnn_node);
+	    if (nn1->efnn_port > 0) nn2->efnn_port = nn1->efnn_port;
+	    else if (nn2->efnn_port > 0) nn1->efnn_port = nn2->efnn_port;
 	}
 	return;
     }