diff --git a/src/string/strlen.c b/src/string/strlen.c
index 929ddcb..bb67699 100644
--- a/src/string/strlen.c
+++ b/src/string/strlen.c
@@ -10,9 +10,18 @@
 size_t strlen(const char *s)
 {
 	const char *a = s;
-	const size_t *w;
+#ifdef __GNUC__
+	typedef size_t __attribute__((__may_alias__)) word;
+
+	const word *w;
 	for (; (uintptr_t)s % ALIGN; s++) if (!*s) return s-a;
+	/* The last access of this loop may be OOB, but falls inside
+	   the same page as a byte of any valid string passed to strlen. */
 	for (w = (const void *)s; !HASZERO(*w); w++);
 	for (s = (const void *)w; *s; s++);
+#else
+	/* Pure C fallback with no OOB access or aliasing violations. */
+	for (; *s; s++);
+#endif
 	return s-a;
 }