diff --git a/src/cpprealm/schema.cpp b/src/cpprealm/schema.cpp
index 6b346f82..5abfb069 100644
--- a/src/cpprealm/schema.cpp
+++ b/src/cpprealm/schema.cpp
@@ -1,4 +1,5 @@
 #include <cpprealm/schema.hpp>
+#include <mutex>
 
 namespace realm {
 namespace schemagen {