diff --git a/cpu/ppc4xx/4xx_enet.c b/cpu/ppc4xx/4xx_enet.c
index 7766f9a..79be865 100644
--- a/cpu/ppc4xx/4xx_enet.c
+++ b/cpu/ppc4xx/4xx_enet.c
@@ -365,6 +365,9 @@
    	out32 (ZMII_FER, (ZMII_FER_RMII | ZMII_FER_MDI) << ZMII_FER_V (devnum));
 #elif defined(CONFIG_440GX)
 	ethgroup = ppc_4xx_eth_setup_bridge(devnum, bis);
+#elif defined(CONFIG_440GP)
+	/* set RMII mode */
+	out32 (ZMII_FER, ZMII_RMII | ZMII_MDI0);
 #else
 	if ((devnum == 0) || (devnum == 1)) {
 		out32 (ZMII_FER, (ZMII_FER_SMII | ZMII_FER_MDI) << ZMII_FER_V (devnum));