Index: src/marclib.cxx
--- src/marclib.cxx.orig
+++ src/marclib.cxx
@@ -442,7 +442,7 @@ int subfcopy(char *To, char *From,int flag)
 /*          returns -1 for no match and 0 for match                 */
 /********************************************************************/
 
-int tagcmp(char *pattag, char *comptag)
+int tagcmp(const char *pattag, const char *comptag)
 {
 	int i;
 	for (i = 0; i < 3; i++) {
@@ -466,7 +466,7 @@ int tagcmp(char *pattag, char *comptag)
 /*            field. Startf lets it start from later in a field list.*/
 /*            Permits "wildcard" comparisons using tagcmp            */
 /*********************************************************************/
-MARC_FIELD *GetField(MARC_REC *rec,MARC_FIELD *startf,char *buffer,char *tag)
+MARC_FIELD *GetField(MARC_REC *rec,MARC_FIELD *startf,char *buffer,const char *tag)
 {
 	MARC_FIELD *f;