diff --git a/drivers/isdn/hisax/tei.c b/drivers/isdn/hisax/tei.c
index 082726d..ceb0df9 100644
--- a/drivers/isdn/hisax/tei.c
+++ b/drivers/isdn/hisax/tei.c
@@ -74,7 +74,7 @@
 	"EV_T202",
 };
 
-unsigned int
+static unsigned int
 random_ri(void)
 {
 	unsigned int x;