diff --git a/drivers/isdn/hardware/avm/c4.c b/drivers/isdn/hardware/avm/c4.c
index d3530f6..9743b24 100644
--- a/drivers/isdn/hardware/avm/c4.c
+++ b/drivers/isdn/hardware/avm/c4.c
@@ -40,7 +40,7 @@
 
 /* ------------------------------------------------------------- */
 
-static int suppress_pollack;
+static bool suppress_pollack;
 
 static struct pci_device_id c4_pci_tbl[] = {
 	{ PCI_VENDOR_ID_DEC, PCI_DEVICE_ID_DEC_21285, PCI_VENDOR_ID_AVM, PCI_DEVICE_ID_AVM_C4, 0, 0, (unsigned long)4 },