diff --git a/source/shared_lib/sources/platform/sdl/thread.cpp b/source/shared_lib/sources/platform/sdl/thread.cpp
index 2871a341..764c28c4 100644
--- a/source/shared_lib/sources/platform/sdl/thread.cpp
+++ b/source/shared_lib/sources/platform/sdl/thread.cpp
@@ -11,9 +11,12 @@
 #include <iostream>
 #include <sstream>
 #include <stdexcept>
+#include <assert.h>
 
 #include "noimpl.h"
 
+using namespace std;
+
 namespace Shared{ namespace Platform{ 
 
 // =====================================
@@ -39,6 +42,10 @@ void Thread::setPriority(Thread::Priority threadPriority) {
 
 int Thread::beginExecution(void* data) {
 	Thread* thread = static_cast<Thread*> (data);
+	assert(thread != NULL);
+	if(thread == NULL) {
+		throw runtime_error("thread == NULL");
+	}
 	thread->execute();
 	return 0;
 }