diff --git a/src/util/single_instance.cpp b/src/util/single_instance.cpp
index 418e52c..31bd6d1 100644
--- a/src/util/single_instance.cpp
+++ b/src/util/single_instance.cpp
@@ -68,7 +68,9 @@ bool SingleInstance::tryLock()
 
 #else
     // Linux/macOS: Use file lock (flock)
-    lock_fd_ = open(lock_path_.c_str(), O_CREAT | O_RDWR, 0666);
+    // O_CLOEXEC: children (xdg-open + the browser it starts, dragonxd, xmrig) must not inherit the lock;
+    // after a crash they'd keep the flock held and block relaunching the wallet.
+    lock_fd_ = open(lock_path_.c_str(), O_CREAT | O_RDWR | O_CLOEXEC, 0666);
     
     if (lock_fd_ < 0) {
         DEBUG_LOGF("Failed to open lock file %s: %s\n", lock_path_.c_str(), strerror(errno));