diff --git a/lib/hashtable.c b/lib/hashtable.c
index 75c263b5053..f96a8e686f6 100644
--- a/lib/hashtable.c
+++ b/lib/hashtable.c
@@ -821,13 +821,12 @@ int himport_r(struct hsearch_data *htab,
 	}
 
 	/* we allocate new space to make sure we can write to the array */
-	if ((data = malloc(size + 1)) == NULL) {
-		debug("himport_r: can't malloc %lu bytes\n", (ulong)size + 1);
+	data = memdup_nul(env, size);
+	if (data == NULL) {
+		debug("himport_r: can't duplicate env block\n");
 		__set_errno(ENOMEM);
 		return 0;
 	}
-	memcpy(data, env, size);
-	data[size] = '\0';
 	dp = data;
 
 	/* make a local copy of the list of variables */