diff --git a/skeletons/tests/check-OIDs.c b/skeletons/tests/check-OIDs.c
index f99310d..58902c3 100644
--- a/skeletons/tests/check-OIDs.c
+++ b/skeletons/tests/check-OIDs.c
@@ -123,9 +123,9 @@
 
 	fprintf(stderr, "Encoding (R) {");
 	for(i = 0; i < acount; i++) {
-		printf(" %u", arcs[i]);
+		fprintf(stderr, " %u", arcs[i]);
 	}
-	printf(" }\n");
+	fprintf(stderr, " }\n");
 
 	ret = RELATIVE_OID_set_arcs(&oid, arcs, sizeof(arcs[0]), acount);
 	assert(ret == 0);
@@ -160,9 +160,9 @@
 
 	fprintf(stderr, "Encoding (O) {");
 	for(i = 0; i < acount; i++) {
-		printf(" %u", arcs[i]);
+		fprintf(stderr, " %u", arcs[i]);
 	}
-	printf(" }\n");
+	fprintf(stderr, " }\n");
 
 	ret = OBJECT_IDENTIFIER_set_arcs(&oid, arcs, sizeof(arcs[0]), acount);
 	assert(ret == 0);