diff --git a/lib/libc/string/bcopy.c b/lib/libc/string/bcopy.c
--- a/lib/libc/string/bcopy.c
+++ b/lib/libc/string/bcopy.c
@@ -40,11 +40,7 @@
 
 #include <sys/types.h>
 
-/*
- * sizeof(word) MUST BE A POWER OF TWO
- * SO THAT wmask BELOW IS ALL ONES
- */
-typedef	int word;		/* "word" used for optimal copy speed */
+typedef	intptr_t word;		/* "word" used for optimal copy speed */
 
 #define	wsize	sizeof(word)
 #define	wmask	(wsize - 1)
@@ -105,7 +101,8 @@
 		 * Copy whole words, then mop up any trailing bytes.
 		 */
 		t = length / wsize;
-		TLOOP(*(word *)dst = *(word *)src; src += wsize; dst += wsize);
+		TLOOP(*(word *)(void *)dst = *(const word *)(const void *)src;
+		    src += wsize; dst += wsize);
 		t = length & wmask;
 		TLOOP(*dst++ = *src++);
 	} else {
@@ -126,7 +123,8 @@
 			TLOOP1(*--dst = *--src);
 		}
 		t = length / wsize;
-		TLOOP(src -= wsize; dst -= wsize; *(word *)dst = *(word *)src);
+		TLOOP(src -= wsize; dst -= wsize;
+		    *(word *)(void *)dst = *(const word *)(const void *)src);
 		t = length & wmask;
 		TLOOP(*--dst = *--src);
 	}