diff --git a/build/CMakeLists.txt b/build/CMakeLists.txt
index 10a53d5..97ffa70 100644
--- a/build/CMakeLists.txt
+++ b/build/CMakeLists.txt
@@ -39,6 +39,9 @@ add_library(aicore STATIC
   ${SRC}/demos/common/gl/app.cpp
   ${SRC}/demos/common/gl/main.cpp
 )
+IF(UNIX)
+	target_link_libraries(aicore -lrt)
+ENDIF(UNIX)
 
 set(DEMO_DEPS aicore ${GLUT_LIBRARY} ${OPENGL_LIBRARY})
 
diff --git a/include/aicore/aicore.h b/include/aicore/aicore.h
index 7fe82da..a12d0d3 100644
--- a/include/aicore/aicore.h
+++ b/include/aicore/aicore.h
@@ -86,3 +86,4 @@
 
 #include "learning.h"
 #include "qlearning.h"
+#include <cstddef>