diff --git a/include/ucore/utils.h b/include/ucore/utils.h
index 9d1e86c..aad8379 100644
--- a/include/ucore/utils.h
+++ b/include/ucore/utils.h
@@ -48,12 +48,14 @@
 //struct foo *f = CONTAINER_OF(p, struct foo, zap);
 #define CONTAINER_OF(ptr, type, member) ({                  \
 typeof( ((type *)0)->member ) *__mptr = (ptr);    \
-    (type *)( (unsigned char *)__mptr - offsetof(type, member) ); })
+    (type *)((void *)(unsigned char *)__mptr - offsetof(type, member) ); })
+
+//the void* cast is to suppress alignment warnings
 
 //Same as CONTAINER_OF, but for a const pointer to avoid gcc warnings..
 #define CONST_CONTAINER_OF(ptr, type, member) ({                  \
 const typeof( ((const type *)0)->member ) *__mptr = (ptr);    \
-    (const type *)( (const unsigned char *)__mptr - offsetof(const type, member) ); })
+    (const type *)((const void *)(const unsigned char *)__mptr - offsetof(const type, member) ); })
 
 /** Align a value.
  * @param val value to align