diff --git a/src/vmemsave.c b/src/vmemsave.c
index ba0720a..0e2aad6 100644
--- a/src/vmemsave.c
+++ b/src/vmemsave.c
@@ -96,7 +96,7 @@ extern int please_fork;
 
 int lispstringP(LispPTR Lisp)
 {
-  switch (((OneDArray *)(Addr68k_from_LADDR(Lisp)))->typenumber) {
+  switch (((OneDArray *)(NativeAligned4FromLAddr(Lisp)))->typenumber) {
     case THIN_CHAR_TYPENUMBER:
     case FAT_CHAR_TYPENUMBER: return (1);