diff --git a/InstructionSets/x86/Instruction.cpp b/InstructionSets/x86/Instruction.cpp
index aff6f03c3..6845888f2 100644
--- a/InstructionSets/x86/Instruction.cpp
+++ b/InstructionSets/x86/Instruction.cpp
@@ -8,6 +8,8 @@
 
 #include "Instruction.hpp"
 
+#include <cassert>
+
 using namespace InstructionSet::x86;
 
 std::string InstructionSet::x86::to_string(Operation operation, DataSize size) {