diff --git a/shell/ash.c b/shell/ash.c
index 9d55f89..ec5e0b8 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -5425,7 +5425,11 @@
 		size_t fulllen = len + strlen(p) + 1;
 
 		if (flag & RMESCAPE_GROW) {
+			int strloc = str - (char *)stackblock();
 			r = makestrspace(fulllen, expdest);
+			/* p and str may be invalidated by makestrspace */
+			str = (char *)stackblock() + strloc;
+			p = str + len;
 		} else if (flag & RMESCAPE_HEAP) {
 			r = ckmalloc(fulllen);
 		} else {