diff --git a/include/asm-ppc/hydra.h b/include/asm-ppc/hydra.h
index 1134431..833a8af 100644
--- a/include/asm-ppc/hydra.h
+++ b/include/asm-ppc/hydra.h
@@ -51,7 +51,7 @@
     char OpenPIC[0x40000];
 };
 
-extern volatile struct Hydra *Hydra;
+extern volatile struct Hydra __iomem *Hydra;
 
 
     /*