diff --git a/lib/krb5/deprecated.c b/lib/krb5/deprecated.c
index 074903ca4..acdc8b476 100644
--- a/lib/krb5/deprecated.c
+++ b/lib/krb5/deprecated.c
@@ -618,7 +618,7 @@ krb5_auth_getremoteseqnumber(krb5_context context,
  * @ingroup krb5_error
  */
 
-KRB5_LIB_FUNCTION char * KRB5_LIB_CALL
+KRB5_LIB_FUNCTION const char * KRB5_LIB_CALL
 krb5_get_error_string(krb5_context context)
     KRB5_DEPRECATED_FUNCTION("Use krb5_get_error_message instead")
 {