diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c
index a7e4939787c9..7f910c76ca0a 100644
--- a/drivers/isdn/hardware/mISDN/hfcpci.c
+++ b/drivers/isdn/hardware/mISDN/hfcpci.c
@@ -1307,11 +1307,11 @@ mode_hfcpci(struct bchannel *bch, int bc, int protocol)
 		}
 		if (fifo2 & 2) {
 			hc->hw.fifo_en &= ~HFCPCI_FIFOEN_B2;
-			hc->hw.int_m1 &= ~(HFCPCI_INTS_B2TRANS +
+			hc->hw.int_m1 &= ~(HFCPCI_INTS_B2TRANS |
 					   HFCPCI_INTS_B2REC);
 		} else {
 			hc->hw.fifo_en &= ~HFCPCI_FIFOEN_B1;
-			hc->hw.int_m1 &= ~(HFCPCI_INTS_B1TRANS +
+			hc->hw.int_m1 &= ~(HFCPCI_INTS_B1TRANS |
 					   HFCPCI_INTS_B1REC);
 		}
 #ifdef REVERSE_BITORDER
@@ -1346,14 +1346,14 @@ mode_hfcpci(struct bchannel *bch, int bc, int protocol)
 		if (fifo2 & 2) {
 			hc->hw.fifo_en |= HFCPCI_FIFOEN_B2;
 			if (!tics)
-				hc->hw.int_m1 |= (HFCPCI_INTS_B2TRANS +
+				hc->hw.int_m1 |= (HFCPCI_INTS_B2TRANS |
 						  HFCPCI_INTS_B2REC);
 			hc->hw.ctmt |= 2;
 			hc->hw.conn &= ~0x18;
 		} else {
 			hc->hw.fifo_en |= HFCPCI_FIFOEN_B1;
 			if (!tics)
-				hc->hw.int_m1 |= (HFCPCI_INTS_B1TRANS +
+				hc->hw.int_m1 |= (HFCPCI_INTS_B1TRANS |
 						  HFCPCI_INTS_B1REC);
 			hc->hw.ctmt |= 1;
 			hc->hw.conn &= ~0x03;
@@ -1375,14 +1375,14 @@ mode_hfcpci(struct bchannel *bch, int bc, int protocol)
 		if (fifo2 & 2) {
 			hc->hw.last_bfifo_cnt[1] = 0;
 			hc->hw.fifo_en |= HFCPCI_FIFOEN_B2;
-			hc->hw.int_m1 |= (HFCPCI_INTS_B2TRANS +
+			hc->hw.int_m1 |= (HFCPCI_INTS_B2TRANS |
 					  HFCPCI_INTS_B2REC);
 			hc->hw.ctmt &= ~2;
 			hc->hw.conn &= ~0x18;
 		} else {
 			hc->hw.last_bfifo_cnt[0] = 0;
 			hc->hw.fifo_en |= HFCPCI_FIFOEN_B1;
-			hc->hw.int_m1 |= (HFCPCI_INTS_B1TRANS +
+			hc->hw.int_m1 |= (HFCPCI_INTS_B1TRANS |
 					  HFCPCI_INTS_B1REC);
 			hc->hw.ctmt &= ~1;
 			hc->hw.conn &= ~0x03;