diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 67f9c157bcc088f67f8f9c73788c4be0560c2cfb..425992e393bc92c2e667fca1a909923e436f399b 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -103,7 +103,7 @@ int of_workarounds;
 #ifdef DEBUG_PROM
 #define prom_debug(x...)	prom_printf(x)
 #else
-#define prom_debug(x...)
+#define prom_debug(x...)	do { } while (0)
 #endif