diff --git a/drivers/net/chelsio/subr.c b/drivers/net/chelsio/subr.c
index 1ebb5d1..12e4e96 100644
--- a/drivers/net/chelsio/subr.c
+++ b/drivers/net/chelsio/subr.c
@@ -686,7 +686,7 @@
  */
 static void __devinit get_pci_mode(adapter_t *adapter, struct chelsio_pci_params *p)
 {
-	static unsigned short speed_map[] = { 33, 66, 100, 133 };
+	static const unsigned short speed_map[] = { 33, 66, 100, 133 };
 	u32 pci_mode;
 
 	pci_read_config_dword(adapter->pdev, A_PCICFG_MODE, &pci_mode);