diff --git a/Core/SoarKernel/src/shared/memory_manager.h b/Core/SoarKernel/src/shared/memory_manager.h
index 8d4ef1a735..2fd33460bd 100644
--- a/Core/SoarKernel/src/shared/memory_manager.h
+++ b/Core/SoarKernel/src/shared/memory_manager.h
@@ -33,6 +33,7 @@
 #include "kernel.h"
 
 #include <unordered_map>
+#include <string>
 
 #ifndef _WIN32
 #include <stdlib.h> // malloc