diff --git a/arch/powerpc/platforms/microwatt/rng.c b/arch/powerpc/platforms/microwatt/rng.c
index 3d8ee6eb7dad..7bc4d1cbfaf0 100644
--- a/arch/powerpc/platforms/microwatt/rng.c
+++ b/arch/powerpc/platforms/microwatt/rng.c
@@ -14,7 +14,7 @@
 
 #define DARN_ERR 0xFFFFFFFFFFFFFFFFul
 
-int microwatt_get_random_darn(unsigned long *v)
+static int microwatt_get_random_darn(unsigned long *v)
 {
 	unsigned long val;