diff --git a/src/gdb/gdb.cc b/src/gdb/gdb.cc
index 795dfca..b6a63af 100644
--- a/src/gdb/gdb.cc
+++ b/src/gdb/gdb.cc
@@ -289,9 +289,9 @@ std::string GDBServer::ReadData(const std::string &msg) {
 
 void *MachineStep(void *vargp) {
 
-  while (true) {
+  while (!(*killed_ptr)) {
     pthread_mutex_lock(&continue_mutex);
-    pthread_cond_wait(&continue_cond, &continue_mutex);
+    pthread_cond_wait(&continue_cond, &continue_mutex); 
     pthread_mutex_unlock(&continue_mutex);
 
     if (*killed_ptr) {