diff --git a/src/SharedMemoryAccess.h b/src/SharedMemoryAccess.h
index 16cde8b..514e46f 100644
--- a/src/SharedMemoryAccess.h
+++ b/src/SharedMemoryAccess.h
@@ -5,6 +5,7 @@
 #ifndef LIBRARY_SHAREDMEMORYACCESSS_H
 #define LIBRARY_SHAREDMEMORYACCESSS_H
 
+int initSemaphore();
 
 /**
  * use lock and unlock when writing
diff --git a/src/vkvm.cpp b/src/vkvm.cpp
index c73c524..f137046 100644
--- a/src/vkvm.cpp
+++ b/src/vkvm.cpp
@@ -10,6 +10,7 @@ void initialize(int pid) {
     impl.sharedMemoryPid = pid;
     impl.sharedMemoryKey = 12345;// NOLINT
     impl.sharedMemorySize = 8000;// NOLINT
+    initSemaphore();
     setDefaultValues();
 }