diff --git a/lib/http_digest.c b/lib/http_digest.c
index 9d1864f1d9b4ff757f31cd222ed7e53a6c5cf059..9d5864496efa2970f839afa2799078cfe88be77a 100644
--- a/lib/http_digest.c
+++ b/lib/http_digest.c
@@ -123,7 +123,7 @@ CURLdigest Curl_input_digest(struct connectdata *conn,
             else if (strequal(token, "auth-int")) {
               foundAuthInt = TRUE;
             }
-            token = strtok (NULL, ",");
+            token = strtok_r(NULL, ",", &tok_buf);
           }
           free(tmp);
           /*select only auth o auth-int. Otherwise, ignore*/