diff --git a/cmd-line-utils/libedit/history.c b/cmd-line-utils/libedit/history.c
index 457c8f4a76803687d57e75cc16c8b0ab9870321d..bae50787b940cfb5570f48ccb15f598a49798dc9 100644
--- a/cmd-line-utils/libedit/history.c
+++ b/cmd-line-utils/libedit/history.c
@@ -647,7 +647,7 @@ history_save(History *h, const char *fname)
 	for (retval = HLAST(h, &ev);
 	    retval != -1;
 	    retval = HPREV(h, &ev), i++) {
-		len = strlen(ev.str) * 4;
+		len = strlen(ev.str) * 4 + 1;
 		if (len >= max_size) {
 			max_size = (len + 1023) & ~1023;
 			ptr = h_realloc(ptr, max_size);