diff --git a/src/perl/PMDA/PMDA.xs b/src/perl/PMDA/PMDA.xs
index a6d16b2..7eaaff1 100644
--- a/src/perl/PMDA/PMDA.xs
+++ b/src/perl/PMDA/PMDA.xs
@@ -1000,8 +1000,7 @@ add_indom(self,indom,insts,help,longhelp)
 	sts = update_indom(insts, p->it_indom, &p->it_set);
 	if (sts < 0)
 	    XSRETURN_UNDEF;
-	if (p->it_set)
-	    p->it_numinst = sts;
+	p->it_numinst = sts;
 	RETVAL = itab_size++;	/* used in calls to replace_indom() */
 
 	hash = pmInDomStr(indom);
@@ -1029,13 +1028,14 @@ replace_indom(self,index,insts)
 	else {
 	    p = indomtab + index;
 	    /* was this indom previously setup via an array? */
-	    if (p->it_set)
+	    if (p->it_set) {
 		release_list_indom(p->it_set, p->it_numinst);
+		p->it_numinst = 0;
+	    }
 	    sts = update_indom(insts, p->it_indom, &p->it_set);
 	    if (sts < 0)
 		XSRETURN_UNDEF;
-	    if (p->it_set)
-		p->it_numinst = sts;
+	    p->it_numinst = sts;
 	    RETVAL = sts;
 	}
     OUTPUT: