diff --git a/include/picrin/xhash.h b/include/picrin/xhash.h
index b43884df..1d3596ca 100644
--- a/include/picrin/xhash.h
+++ b/include/picrin/xhash.h
@@ -21,7 +21,7 @@ extern "C" {
 #define XHASH_RESIZE_RATIO 0.75
 
 #define XHASH_ALIGNMENT 3       /* quad word alignment */
-#define XHASH_MASK (~((1 << XHASH_ALIGNMENT) - 1))
+#define XHASH_MASK (~(size_t)((1 << XHASH_ALIGNMENT) - 1))
 #define XHASH_ALIGN(i) ((((i) - 1) & XHASH_MASK) + (1 << XHASH_ALIGNMENT))
 
 typedef struct xh_entry {
@@ -325,7 +325,7 @@ xh_ptr_hash(const void *key, void *data)
 {
   (void)data;
 
-  return (size_t)*(const void **)key;
+  return (int)(size_t)*(const void **)key;
 }
 
 static inline int
diff --git a/include/picrin/xvect.h b/include/picrin/xvect.h
index b98886e9..3701205e 100644
--- a/include/picrin/xvect.h
+++ b/include/picrin/xvect.h
@@ -45,7 +45,7 @@ xv_init(xvect *x, size_t width)
   x->data = NULL;
   x->width = width;
   x->size = 0;
-  x->mask = -1;
+  x->mask = (size_t)-1;
   x->head = 0;
   x->tail = 0;
 }