diff --git a/src/intl/charsets.c b/src/intl/charsets.c
index 6df8e8ad..34f326d2 100644
--- a/src/intl/charsets.c
+++ b/src/intl/charsets.c
@@ -988,7 +988,7 @@ compare_entities(const void *key_, const void *element_)
 	return xxstrcmp(first, second, length);
 }
 
-unsigned char *
+const unsigned char *
 get_entity_string(const unsigned char *str, const int strlen, int encoding)
 {
 #define ENTITY_CACHE_SIZE 10	/* 10 seems a good value. */
diff --git a/src/intl/charsets.h b/src/intl/charsets.h
index edae15f6..db123a24 100644
--- a/src/intl/charsets.h
+++ b/src/intl/charsets.h
@@ -72,7 +72,8 @@ enum nbsp_mode {
 };
 
 struct conv_table *get_translation_table(int, int);
-unsigned char *get_entity_string(const unsigned char *str, const int strlen, int encoding);
+const unsigned char *get_entity_string(const unsigned char *str,
+				       const int strlen, int encoding);
 
 /* The convert_string() name is also used by Samba (version 3.0.3), which
  * provides libnss_wins.so.2, which is called somewhere inside