diff --git a/uppsrc/Core/CoWork.cpp b/uppsrc/Core/CoWork.cpp
index 46e49dc15..1c3ceb3fd 100644
--- a/uppsrc/Core/CoWork.cpp
+++ b/uppsrc/Core/CoWork.cpp
@@ -113,7 +113,7 @@ void CoWork::Pool::DoJob(MJob& job)
 	}
 
 	lock.Leave();
-	std::exception_ptr exc;
+	std::exception_ptr exc = nullptr;
 	try {
 		if(looper)
 			work->looper_fn();
diff --git a/uppsrc/Core/CoWork.h b/uppsrc/Core/CoWork.h
index b858ca261..454406168 100644
--- a/uppsrc/Core/CoWork.h
+++ b/uppsrc/Core/CoWork.h
@@ -57,7 +57,7 @@ public:
 	Link<MJob, 2>      jobs; // global stack and CoWork stack as double-linked lists
 	int                todo;
 	bool               canceled;
-	std::exception_ptr exc;
+	std::exception_ptr exc = nullptr; // workaround for sanitizer bug(?)
 	Function<void ()>  looper_fn;
 	int                looper_count;