diff --git a/Components/OPL2/OPL2.cpp b/Components/OPL2/OPL2.cpp
index 1985e9f56..d5677dd96 100644
--- a/Components/OPL2/OPL2.cpp
+++ b/Components/OPL2/OPL2.cpp
@@ -8,6 +8,7 @@
 
 #include "OPL2.hpp"
 
+#include <cassert>
 #include <cmath>
 
 namespace {