diff --git a/src/parser/subparser.cpp b/src/parser/subparser.cpp
index 50bf17e..f6bd440 100644
--- a/src/parser/subparser.cpp
+++ b/src/parser/subparser.cpp
@@ -1486,18 +1486,22 @@ void explodeClash(Node yamlnode, std::vector<Proxy> &nodes) {
                 singleproxy["password"] >>= password;
                 if (password.empty())
                     singleproxy["auth"] >>= password;
-                singleproxy["up"] >>= up;
-                if (up.empty()) {
-                    try {
-                        up = singleproxy["up"].as<std::string>();
-                    } catch (const YAML::BadConversion& e) {
+                if (singleproxy["up"].IsDefined()) {
+                    singleproxy["up"] >>= up;
+                    if (up.empty()) {
+                        try {
+                            up = singleproxy["up"].as<std::string>();
+                        } catch (const YAML::BadConversion& e) {
+                        }
                     }
                 }
-                singleproxy["down"] >>= down;
-                if (down.empty()) {
-                    try {
-                        down = singleproxy["down"].as<std::string>();
-                    } catch (const YAML::BadConversion& e) {
+                if (singleproxy["down"].IsDefined()) {
+                    singleproxy["down"] >>= down;
+                    if (down.empty()) {
+                        try {
+                            down = singleproxy["down"].as<std::string>();
+                        } catch (const YAML::BadConversion& e) {
+                        }
                     }
                 }
                 singleproxy["obfs"] >>= obfsParam;