diff --git a/ssh-gss.h b/ssh-gss.h
index c29a1b7..077e13c 100644
--- a/ssh-gss.h
+++ b/ssh-gss.h
@@ -42,12 +42,13 @@
 #   include <gssapi/gssapi_generic.h>
 #  endif
 
-/* MIT Kerberos doesn't seem to define GSS_NT_HOSTBASED_SERVICE */
+/* Old MIT Kerberos doesn't seem to define GSS_NT_HOSTBASED_SERVICE */
 
-#ifndef GSS_C_NT_HOSTBASED_SERVICE
-#define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name
-#endif /* GSS_C_NT_... */
-#endif /* !HEIMDAL */
+#  if !HAVE_DECL_GSS_C_NT_HOSTBASED_SERVICE
+#   define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name
+#  endif /* !HAVE_DECL_GSS_C_NT_... */
+
+# endif /* !HEIMDAL */
 #endif /* KRB5 */
 
 /* draft-ietf-secsh-gsskeyex-06 */