diff --git a/skeletons/OBJECT_IDENTIFIER.c b/skeletons/OBJECT_IDENTIFIER.c
index 7c9c980..0c16bfd 100644
--- a/skeletons/OBJECT_IDENTIFIER.c
+++ b/skeletons/OBJECT_IDENTIFIER.c
@@ -652,7 +652,7 @@
 
 int
 OBJECT_IDENTIFIER_parse_arcs(const char *oid_text, ssize_t oid_txt_length,
-	long *arcs, unsigned int arcs_slots, const char **oid_text_end) {
+	long *arcs, unsigned int arcs_slots, const char **opt_oid_text_end) {
 	unsigned int arcs_count = 0;
 	const char *oid_end;
 	long value = 0;
@@ -663,7 +663,7 @@
 	} state = ST_SKIPSPACE;
 
 	if(!oid_text || oid_txt_length < -1 || (arcs_slots && !arcs)) {
-		if(oid_text_end) *oid_text_end = oid_text;
+		if(opt_oid_text_end) *opt_oid_text_end = oid_text;
 		errno = EINVAL;
 		return -1;
 	}
@@ -715,7 +715,7 @@
 	} /* for() */
 
 
-	if(oid_text_end) *oid_text_end = oid_text;
+	if(opt_oid_text_end) *opt_oid_text_end = oid_text;
 
 	/* Finalize last arc */
 	switch(state) {
diff --git a/skeletons/OBJECT_IDENTIFIER.h b/skeletons/OBJECT_IDENTIFIER.h
index e32ecef..c1c9e2c 100644
--- a/skeletons/OBJECT_IDENTIFIER.h
+++ b/skeletons/OBJECT_IDENTIFIER.h
@@ -105,8 +105,8 @@
  * If (oid_txt_length == -1), the strlen() will be invoked to determine the
  * size of the (oid_text) string.
  * 
- * After return, the optional (oid_text_end) is set to the character after
- * the last parsed one. (oid_text_end) is never less than (oid_text).
+ * After return, the optional (opt_oid_text_end) is set to the character after
+ * the last parsed one. (opt_oid_text_end) is never less than (oid_text).
  * 
  * RETURN VALUES:
  *   -1:	Parse error.
@@ -117,7 +117,7 @@
  * This is useful for (_arc_slots) value estimation.
  */
 int OBJECT_IDENTIFIER_parse_arcs(const char *oid_text, ssize_t oid_txt_length,
-	long arcs[], unsigned int arcs_slots, const char **oid_text_end);
+	long arcs[], unsigned int arcs_slots, const char **opt_oid_text_end);
 
 /*
  * Internal functions.